Melbourne: Novak Djokovic flirted with a shock elimination in a five-set thriller with Gilles Simon before he reached the Australian Open quarter-finals to stay on track for a record-equalling sixth title on Sunday.
The world number one has become the dominant force in men`s tennis but he was pushed all the way by the relentless Simon before taking it 6-3, 6-7 (1/7), 6-4, 4-6, 6-3 to set up a clash with Kei Nishikori.
It wasn`t the only marathon five-setter on Sunday as Tomas Berdych outlasted Spain`s Roberto Bautista Agut 4-6, 6-4, 6-3, 1-6, 6-3 to go into a quarter-final against Roger Federer or David Goffin.
By comparison, Nishikori`s win was a stroll as he crushed Jo-Wilfried Tsonga in straight sets, and he may fancy his chances against top-ranked Djokovic who clocked 100 unforced errors in a flustered performance.
The 10-time Grand Slam champion was detained on court for four hours, 32 minutes in what was his first five-set match since he beat Kevin Anderson in the Wimbledon fourth round last year.
"Playing someone like Gilles, you face a lot of balls coming back. You expect a lot of rallies and he`s always making you play an extra shot," Djokovic said.
"I made a lot of unforced errors today but nevertheless he was always fighting. It was a four-and-a-half-hour match and physically demanding."
Tuesday`s clash will be Djokovic and Nishikori`s first Grand Slam meeting since the 2014 US Open semis, when the Japanese player won in four sets to become the first Asian man to reach a major singles final.
Djokovic hadn`t lost to Simon in nine matches stretching back to 2008, but the Frenchman`s patient probing and counter-punching rattled the game`s top player.
The Serb took nearly an hour to win the first set and his frustrations were palpable as Simon took the second on a tiebreak, ending an unbeaten sequence of 26 sets stretching back to the World Tour Finals.
He got the crucial break to take the third set but the persistent Simon took it into a fifth after he broke in the ninth game of the fourth set, amid another flurry of errors from the Serb.
Djokovic got two service breaks in the fifth set only to be broken back once, but he finally clinched victory on his third match point with a backhand winner.Earlier Nishikori produced his best tennis of the tournament to breeze past former finalist Tsonga 6-4, 6-2, 6-4 in just over two hours on Hisense Arena.
"Today was one of the best matches I`ve had this week. Played good tennis, through in three sets," beamed Nishikori, who showed no sign of his troublesome right wrist injury.
Meanwhile, Berdych was also taken the distance by a dogged Bautista Agut before he finally put him away after three hours, 18 minutes to reach the last eight at Melbourne Park for a sixth straight year.
Berdych has been a semi-finalist for the last two years in Melbourne and the Australian Open has proved the Czech`s most successful Grand Slam based on match wins, now standing at 38-12.
It was his fourth win in six meetings with Bautista Agut, who upset former US Open champion and 12th seed Marin Cilic to reach the round of 16.
"I think this is my best start to the year. It`s a good one so far, I`ve got past the first week and now all the focus is on the second week," said the Czech.