Melbourne - Defending champion Novak Djokovic survived an early onslaught and a late fightback from Stanislas Wawrinka in a pulsating fourth-round clash to advance to the quarter-finals of the Australian Open early on Monday (Australian time).
The 15th-seeded Swiss had taken an early 6-1, 5-2 lead over the world No 1 with a powerful serve and booming groundstrokes before Djokovic took greater control of the rallies and waited for Wawrinka to make mistakes.
Wawrinka, however, managed to send the match into a decider when he totally dominated the fourth set tie-break before Serbian clinched a 1-6, 7-5, 6-4, 6-7 (5/7), 12-10 victory on his third match point with a cross-court backhand winner.
The match, which lasted five hours and two minutes, finished at 01:40 Australian time.
"It's really hard to find the words to describe the feeling," an exhausted Djokovic said courtside.
"He deserved equally to be a winner of this match. I give him a lot of credit. He showed his qualities.
"He was the aggressive player on the court. He was playing well, mixing it up, using the right tactics and serving really well.
"I was just trying to hang in there and fight and give every drop of energy."
Djokovic, seeking to become the first man in the professional era to win three successive Australian Open titles, will now meet fifth seed Tomas Berdych in the quarter-finals.
Wawrinka had lost his 10 previous encounters against Djokovic but did not appear overawed by the occasion or the world No 1.
He mixed up the pace of his returns, painted the tramlines and launched ground-shots from both wings that had the crowd in Rod Laver Arena ooh-ing, ah-ing and looking at neighbours wondering if what they were watching was real.
He broke Djokovic three times to claim the first set 6-1 in 25 minutes and, while he had his serve broken in the first game of the second set, the setback was temporary as he then reeled off the next four games.
Djokovic, who had changed his shoes after the third game of the second set because he was constantly slipping over, however finally held serve at 4-2, which sparked a recovery.
The top seed won five of the next six games to take the set 7-5 and level the match, then broke in the first game of the third that produced an almighty roar from the Serb.
While Wawrinka broke back immediately, both players then seemed to take a breather and the match settled down with Djokovic taking greater control of the rallies, reducing Wawrinka's ability to go for winners and waiting for him to make errors.
The tactic worked as he broke in the ninth game of the third set then held serve to take it 6-4 before the match quickly advanced through the fourth as both held serve until the tiebreak, which Wawrinka dominated.
Neither were able to hold their first service games in the fifth set and it then became a case of who would blink first with Djokovic holding a break point in the eighth game only for Wawrinka to hold his nerve.
Wawrinka had four chances to break at 4-4 in the fifth set but was unable to capitalise. He was unlucky on one of those points though when his ball was wrongfully called out. Replays showed it had in fact painted the line but the Swiss refrained from using the one challenge he still had at his disposal.
The match then stayed on serve until the 22nd game of the set, where Djokovic held three match points before he finally sealed the win, raised his arms and let out another almighty bellow of relief.
"It could have gone either way this match and I am thrilled to be through," Djokovic added.
"He had a lot of chances to win this match. All the credit to him, I feel sorry that one of us had to lose."
Results from day seven of the Australian Open:
Ekaterina Makarova (RUS x19) bt Angelique Kerber (GER x5) 7-5, 6-4
Maria Sharapova (RUS x2) bt Kirsten Flipkens (BEL) 6-1, 6-0
Li Na (CHN x6) bt Julia Goerges (GER x18) 7-6 (8/6), 6-1
Agnieszka Radwanska (POL x4) bt Ana Ivanovic (SRB x13) 6-2, 6-4
David Ferrer (ESP x4) bt Kei Nishikori (JPN x16) 6-2, 6-1, 6-4
Nicolas Almagro (ESP x10) bt Janko Tipsarevic (SRB x8) 6-2, 5-1 ret
Tomas Berdych (CZE x5) bt Kevin Anderson (RSA) 6-3, 6-2, 7-6 (15/13)
Novak Djokovic (SRB x1) bt Stanislas Wawrinka (SUI x15) 1-6, 7-5, 6-4, 6-7 (5/7), 12-10