Novak Djokovic was nowhere near his brilliant best, but came through a marathon five-setter to beat Gilles Simon in the fourth round of the Australian Open, before Roger Federer sailed into the quarter-finals at a canter.
World number one Djokovic needed over four and a half hours to finally overcome 14th seed Simon at Rod Laver Arena 6-3 6-7 (7-1) 6-4 4-6 6-3, but Federer was in no mood to hang around as he eased past David Goffin under the lights.
Tomas Berdych was also taken all the way by Roberto Bautista Agut and expressed his grievance with the umpire when he wanted a point replayed after low-flying birds hit the net, but eventually soared into the last eight.
Top seed Djokovic has become the dominant force in men's tennis, but failed to match his usual standards as he made hard work of seeing off Simon.
The five-time champion in Melbourne remains on course to defend his title, but was not as clinical in an error-strewn display. However, Simon was unable to pull off a huge upset.
Federer was clearly in a hurry to reach the last eight, as he needed only 88 minutes to come out on top in a one-side encounter with Belgian Goffin.
SEEDS SAYING GOODBYE
Jo-Wilfried Tsonga was the highest seeded player to exit the first grand slam of the year, with the 2008 Australian Open runner-up going down in straight sets to Kei Nishikori.
An out-of-sorts Djokovic made an astonishing 100 unforced errors, but also produced 62 winners to match on.
The Serb has now reached at least the quarter-final stage in his last 27 grand slams.
Federer has now reached the last eight in Melbourne 12 times, while Berdych has featured in the quarer-finals of the tournament in each of the last six years.
SOCIAL MEDIA SWEEP
Berdych tweeted a picture of himself grinning in a bath with an umbrella up eating dinner and posted: "#ausopen #postmatch #recovery #dinner."
After Lleyton Hewitt's career came to an end, his former coach Darren Cahill gave the Australian a glowing tribute. "His average was never average. His will to win was an obsession. His willingness to compete an inspiration. Congrats Rusty @lleytonhewitt."
THEY SAID WHAT?
Djokovic was well aware of his shortcomings on Sunday, saying: "In terms of a level that I've played, it's the match to forget for me. But you have days like this, fortunately you manage to fight your way through. It's not a very pleasant feeling when you're not playing well. But certainly it's a good feeling when you win not playing well."
Tsonga gave an honest assessment following his defeat to Nishikori, stating: "I think he was just better than me on the three sets."
Looking forward to his next match, Berdych said: "It's the quarter-final of a slam. Yeah, I like it. I like my chances. I'm just looking forward to that match."
Djokovic will take on Nishikori in the quarter-finals, while Berdych is Federer's last-eight opponent.
Novak Djokovic (1) beat Gilles Simon (14) 6-3 6-7 (1-7) 6-4 4-6 6-3
Roger Federer (3) beat David Goffin (15) 6-2 6-1 6-4
Tomas Berdych (6) beat Roberto Bautista Agut (24) 4-6 6-4 6-3 1-6 6-3
Kei Nishikori (7) beat Jo-Wilfried Tsonga (9) 6-4 6-2 6-4