The choice of song could hardly have been more appropriate. Almost every part of Novak Djokovic's body was aching when he made an appearance at the post-tournament staff party here at the Australian Open, in the early hours of yesterday morning, but the champion summoned up the energy to belt out his own version of AC/DC's "Highway to Hell".
After beating Rafael Nadal in an extraordinary match that finished at 1.37am and lasted five hours and 53 minutes – nearly an hour longer than the previous record for a Grand Slam final – Djokovic did not get to bed until 8am. Still on a mental high despite his physical exhaustion, the 24-year-old Serb even watched television highlights of his 5-7, 6-4, 6-2, 6-7, 7-5 victory before going to sleep.
Just a few hours later, dressed in shorts, a tracksuit top and flip-flops, Djokovic was back at Melbourne Park to meet the media.
"Oh man, I'm tired," he said. "The adrenalin is still there and I'm still very excited about what I have experienced here in the last two weeks and especially last night. I'm full of joy, but I think I still don't have a real sense of what's going on."
At the next Grand Slam tournament, the French Open, Djokovic will attempt to become the first man since Rod Laver in 1969 to hold all four major titles at once. Nor does the world No 1 rule out the possibility of becoming the first man since Laver to win a pure "Grand Slam", of all four major titles in the same year. He could even contemplate emulating Steffi Graf's "Golden Slam" of 1988, when she won all four majors and Olympic gold.
"It is possible," Djokovic said, when asked about his chance of matching Laver. "Obviously, the times are different and tennis nowadays is much more competitive and much more physical. And that makes that challenge more difficult to achieve. But everything is possible.
"The facts are that I'm at the peak of my career. I feel physically and mentally at the peak. I feel strong, I feel motivated, I feel eager to win more trophies."
Djokovic said he would take one tournament at a time this year but intended to focus his energies on the Grand Slam events and the London Olympics. He came close to emulating Laver last year, when his only defeat in a Grand Slam tournament was against Roger Federer in the semi-finals at Roland Garros. Djokovic may have paid the price in Paris for his efforts in the spring, after going 41 matches unbeaten at the start of the year and winning titles in Dubai, Indian Wells, Miami, Belgrade, Madrid and Rome before heading for Roland Garros.
Until the start of last year Djokovic's career appeared to have reached a plateau. He arrived here having not won a Grand Slam title for three years, following his first triumph at the Australian Open. Despite almost invariably being in contention in the latter stages of all the major tournaments, he appeared unable to bridge the gap between himself and the world's top two, Nadal and Federer.
However, Djokovic came here 12 months ago with his confidence boosted by Serbia's Davis Cup triumph at the end of 2010 and his physical resilience – which had regularly been called into question in the past – strengthened by his gluten-free diet.
"When I played three or four years ago against Rafa and Roger in Grand Slam semi-finals and finals, I felt that they were just superior on the court, that they had this mental advantage," he said. "Because they just know that when the time comes, when the match is breaking down, fifth set, they will always prevail, because they believe more, they have more experience and they know what to do."
Yesterday's updated world rankings list maintained the statistical status quo at the top, with Djokovic at No 1, Nadal at No 2, Federer at No 3 and Andy Murray at No 4. On the evidence of the last fortnight, a thrilling and hugely competitive season is in store. If questions remain as to whether 30-year-old Federer will ever add to his record Grand Slam haul – he has not won any of the last eight tournaments – the competition between the 25-year-old Nadal and the two 24-year-olds, Djokovic and Murray, is likely to be intense.
The last three matches here – Nadal's semi-final victory over Federer and Djokovic's over Murray, plus the final itself – were arguably the greatest three contests ever at the end of a Grand Slam tournament, underlining the gap the four men have opened up over the rest of the men's game. While Federer (16 Grand Slam titles), Nadal (10) and Djokovic (five) can be regarded as being in an elite group of their own, Murray is right up with them in everything but claiming the ultimate prizes.
Nadal took great heart from his display on Sunday, pointing out that he had stretched Djokovic more than in any of his six defeats by the Serb in finals in 2011. Murray will also derive encouragement from his performances here, despite the fact that he failed to match his feat of reaching the final in 2010 and 2011. In his semi-final Murray came closer to beating Djokovic than Nadal did – the Scot was within five points of victory whereas Nadal was six points away – and looked more like a potential Grand Slam champion than at any stage of his career.
The positive influence of Ivan Lendl, Murray's new coach, is clear, despite the fact that they have had only one month together. Murray plans to train with Lendl in Miami next month in the build-up to his next tournament, in Dubai in four weeks' time. The world No 4 has yet to make a decision about whether to play in Britain's Davis Cup tie against Slovakia at the end of next week. If he plays, matches against the likes of Lukas Lacko and Martin Klizan in a shopping mall in Glasgow will seem a far cry from the momentous tennis we have seen here for the last fortnight.
Djokovic v Nadal: the Twitter verdict
"Djokovic-Rafa. Absolute war. Physicality of tennis has been taken to another level in the last 5 years. 6 straight hours of power/speed" - Andy Roddick
"No words for the match... the level of tennis is getting higher and higher...Congratz to both... True champions" - Janko Tipsarevic
"It's a war out there!" - Jimmy Connors
"Is there or has there ever been a tennis player with more will power than Rafael Nadal?" - Jamie Murray
"Amazed at the last 3 men's matches, 14 sets, epic weekend?" - Brad Gilbert
"Still cannot believe I am awake...unbelievable match, I love tennis!!!!" - Novak Djokovic, 5am yesterday