Nadal's victory brought him his third US Open crown and 16th Grand Slam title
Rafael Nadal put his remarkable resurgence down to his "love for the game" after claiming a 16th Grand Slam title at the US Open.
The 31-year-old Spaniard beat South Africa's Kevin Anderson 6-3 6-3 6-4 to win his third title in New York.
Following his French Open success in June, it is the first time since 2013 that Nadal has won two Slams in a year.
"I wake up every morning with the passion to go on court and to try to improve things," he said.
"I still want to compete and still feel the nerves every time that I go on court. While that keeps happening, I will be here.
"When some day arrives that I don't feel the nerves or that extra passion for the game that I feel, it will be the day to say, 'OK, I do another thing.'
"I am 31, I'm not 25, but I still have the passion and the love for the game."
Match stats
Nadal
Anderson
1
Aces
10
1
Double faults
4
63%
First serve
59%
84%
Pts won on 1st serve
73%
70%
Pts won on 2nd serve
36%
30
Winners
32
11
Unforced errors
40
Nadal's victory took him three away from Roger Federer's all-time record of 19 Grand Slam titles, and the pair shared all four major victories between them in 2017.
That came after both men ended their 2016 seasons early through injury, casting doubts on their ability to even challenge for the biggest titles again.
"I just can say thanks to life for that opportunity," said Nadal.
"Probably that's why I still have chances to compete in this sport and to do it well. That's all."
Grand Slams: Rafa v Roger
Had Nadal converted his lead over Federer, 36, in the final set of this year's Australian Open final in January, there would be just one major title between the pair.
"I really never thought much about that," said the Spaniard. "I just do my way. He does his way. Let's see when we finish.
"Three is a big difference. I really don't think much about these kind of things.
"I'm very happy with all the things that are happening to me, to win this title again. I have this trophy with me."
Coaching changes in Nadal camp
Tiger Woods - a 14-time winner of golf's majors - supported Nadal in Sunday's final
The US Open was the last Grand Slam tournament in which Nadal was accompanied by his uncle Toni, the man who first put a racquet in his hand when was three years old.
Former world number one Carlos Moya, a close friend of Nadal, will take on coaching duties alongside long-time team member Francis Roig from next year.
Toni Nadal will take on the running of his nephew's tennis academy in Majorca, which opened last year, although the world number one did not completely rule out a return to the player box for his uncle.
"He's going to stop and going to put more attention on the academy. That would be great for my academy, and will be great for the kids," said Nadal.
"That doesn't mean that Toni will not travel any more. No, no, I believe that it will be stupid to say that.
"But of course he will not be in the diary of my practices and of my travels."
In the small Chinese city of Yanji, the ground was moving.
This Korean-speaking region sits on the border with North Korea and soon local bloggers were posting images on social media of things shaking.
What they could not have known was that this earthquake was man-made.
Not far away, the government in Pyongyang was soon declaring the successful test of a hydrogen bomb - its most powerful to date.
The timing was a clear slap in the face for Beijing.
Just hours after the underground nuclear test, President Xi Jinping was due to make a speech as the head of state for the nation hosting the Brics summit, which would welcome delegates from Brazil, Russia, India and South Africa to Xiamen.
It is conceivable that North Korea did not necessarily choose the opening day of this major diplomatic gathering for its test but it certainly did not see the need to call it off for fear of offending China.
And, what is more, these weapons test "coincidences" are now starting to mount up when it comes to Xi Jinping.
In March, just before the Chinese leader was set to meet United States Secretary of State Rex Tillerson in Beijing, North Korea announced the successful test of a new type of rocket engine.
Another coincidence?
Then in May President Xi was preparing to open the One Belt One Road forum. The leaders of dozens of nations had come to the Chinese capital to discuss economic development and transport infrastructure around the Chinese leader's signature foreign policy initiative. Then, whoooooosh! Off goes another North Korean missile test to steal the limelight before the summit could even get going.
That this could have happened again with the Brics summit is incredible.
Xi Jinping - who is also the chair of the Central Military Commission in China - cannot be happy with this emerging pattern.
Image copyrightREUTERSImage captionPeople look across to North Korea from Tumen
The North Koreans, in turn, would be furious with the behaviour of their old Cold War allies. China has not only backed sanctions against them in the United Nations Security Council but, as the isolated regime's principal trading partner, it has also been the principal implementer of these sanctions, turning back coal shipments and the like.
How China could fight back
Yet most observers know that, if it really wanted to, Beijing could bring crippling economic pain to North Korea. Heading into winter, it could freeze oil and gas supplies.
Then there are the banks.
North Korea is thought to conduct an enormous amount of laundered business via Chinese financial institutions. Various front businesses have been set up to facilitate money and products to flow in and out of the country with the assistance of these bodies. The Chinese government cannot be unaware of this and they could pull the plug on it tomorrow if they wanted to.
But they don't for one reason.
The Chinese government does not like the regional instability that their neighbour's nuclear weapons testing programme brings, but Beijing fears something even more.
Media captionNorth Korean state media announces "hydrogen bomb" test
They worry that total regime collapse in Pyongyang, leading to a unified Korean Peninsula dominated by the South, could lead to US troops on the border within marching distance of Yanji and they will put up with an awful lot from the Democratic People's Republic of Korea as long as this does not happen.
The Environment Ministry here has announced that it has now started "emergency radiation testing" along the frontier. The government's displeasure would be significant if Chinese territory has been contaminated.
The Chinese Foreign Ministry's official response to this latest North Korean nuclear weapons test condemned it strongly but, with increasingly loud calls coming for this country to do more to pressure Kim Jong-un to give up intercontinental ballistic missile ambitions, there would be serious frustration within the upper echelons of the Chinese Communist Party as to what they can realistically do next.
The North Korean leader has made his nuclear ambitions a hallmark of his administration to the extent that it is hard to see what type of offering or threat could alter this situation.
That is, unless the US and China have come up with a secret agreement which would see American troops leave Korea in the event of unification… if that was in place it could change everything.
But speaking to reporters outside the White House, Defence Secretary Mattis said the US had the ability to defend itself and its allies South Korea and Japan, adding that its commitments were "ironclad".
"Any threat to the United States or its territories - including Guam - or our allies will be met with a massive military response, a response both effective and overwhelming."
Media captionNuclear N Korea: What do we know?
However, he said the hope was for denuclearisation, "because we are not looking to the total annihilation of a country, namely North Korea".
The UN Security Council is to hold an emergency meeting on Monday to discuss an international response, according to the US mission.
Meanwhile, President Trump has warned that America may stop trading with any country that does business with the North.
What has happened?
The first suggestion that this was to be a far from normal Sunday in the region came when seismologists' equipment started picking up readings of an earth tremor in the area where North Korea has conducted nuclear tests before.
The US Geological Survey put the tremor at 6.3 magnitude.
Japanese Foreign Minister Taro Kono said there was no doubt this was North Korea's sixth nuclear test, calling it "unforgivable".
Then North Korean state media confirmed this was no earthquake.
It claimed the country had conducted its sixth and most powerful nuclear test, detonating a hydrogen bomb that could be loaded onto a long-range missile.
Media captionNorth Korean state media announces "hydrogen bomb" test
North Korean leader Kim Jong-un was pictured with what state media said was a new type of hydrogen bomb.
Hydrogen bombs are many times more powerful than an atomic bomb. They use fusion - the merging of atoms - to unleash huge amounts of energy, whereas atomic bombs use nuclear fission, or the splitting of atoms.
Analysts say the North's claims should be treated with caution, but that its nuclear capability is clearly advancing.
Officials in China, where the blast was felt as a tremor, said they were carrying out emergency radiation testing along the border with North Korea.
What has the reaction been?
Denouncing the test as "hostile" and "dangerous", President Trump described the North as a "rogue nation" which had become a "great threat and embarrassment" to China - Pyongyang's main ally.
He also said South Korea's "talk of appeasement" was not working and that the secretive communist state "only understands one thing".
"The United States is considering, in addition to other options, stopping all trade with any country doing business with North Korea," Mr Trump later said in a tweet. North Korea relies on China for about 90% of its foreign trade.
Image copyrightREUTERS/KCNAImage captionState media showed North Korean leader Kim Jong-un inspecting what it said was a hydrogen bomb
South Korean President Moon Jae-in called for the "strongest possible" response, including new UN Security Council sanctions to "completely isolate" the country.
The country staged a "live-fire exercise" late on Sunday simulating an attack on the North's Punggye-ri nuclear site, military officials said.
The drill saw a Hyunmoo surface-to-surface missile and air-to-ground missiles fired from F-15K jets hit targets in the East Sea, also known as the Sea of Japan, according to the Joint Chiefs of Staff quoted by Yonhap news agency.
China, meanwhile, also expressed "strong condemnation" and said the state "had ignored the international community's widespread opposition".
Russia urged all sides involved to hold talks, saying this was the only way to resolve the Korean peninsula's problems.
UK Prime Minister Theresa May said the "reckless" new test represented an "unacceptable further threat to the international community". She called on world leaders to come together to stop North Korea's "destabilising actions".
What does the test tell us?
South Korean officials said the latest test took place in Kilju County, where the North's Punggye-ri nuclear test site is situated. The "artificial quake" was 9.8 times more powerful than the tremor from the North's fifth test in September 2016, the state weather agency said.
Although experts urged caution, this does appear to be the biggest and most successful nuclear test by North Korea to date - and the messaging is clear. North Korea wants to demonstrate it knows what makes a credible nuclear warhead.
North Korea's nuclear tests
Nuclear weapons expert Catherine Dill told the BBC it was not yet clear exactly what nuclear weapon design was tested.
"But based on the seismic signature, the yield of this test definitely is an order of magnitude higher than the yields of the previous tests."
Current information did not definitively indicate that a thermonuclear weapon had been tested "but it appears to be a likely possibility at this point", she said
What can be done?
By Jonathan Marcus, BBC defence and diplomatic correspondent
North Korea's sixth nuclear test - probably its largest so far - sends out one clear political signal.
Despite the bluster and threats from the Trump administration in Washington and near-universal condemnation from around the world, Pyongyang is not going to halt or constrain its nuclear activities.
Worryingly, it also suggests that this is a programme that is progressing on all fronts at a faster rate than many had expected. So far all efforts to pressure North Korea - sanctions, isolation and military threats - have all failed to move Pyongyang.
Could more be done? Certainly, but the harshest economic pressure would potentially cripple the regime and push it towards catastrophe - something China is unwilling to countenance.
Containment and deterrence will now come to the fore as the world adjusts its policy from seeking to roll-back Pyongyang's weapons programme to living with a nuclear-armed North Korea.
Media captionSpeaking before the new nuclear test, Senator Lindsey Graham told BBC HARDtalk a US attack was inevitable if diplomacy failed
Will China clamp down?
By Robin Brant, BBC News, Shanghai
North Korea's sixth nuclear weapons test is an utter rejection of all that its only ally has called for.
Beijing's response was predictable - condemnation, urging an end to provocation and dialogue. But it also spoke of urging North Korea to "face up to the firm will" of the international community to see denuclearisation on the Korean peninsula.
There is no sign, though, that China is willing yet to see that "firm will" go beyond UN sanctions, which recently clamped down on seafood and iron ore exports, in addition to the coal and minerals that are already banned from crossing the border.
It is noteworthy also that this test took place just as the Chinese president was about to welcome a handful of world leaders to the two-day showpiece Brics summit on China's east coast.
Even the state-controlled media will find it hard to ignore the fact that their man has been upstaged - embarrassed too - by its almost universally ostracised ally and neighbour.
