Potential quarter-final opponents Roger Federer and Andy Murray secured straightforward second-round wins at the Australian Open, on a day where Andreas Seppi and Nick Kyrgios were involved in another five-set classic.

Two years ago, home favourite Kyrgios and Seppi met in the fourth round, the Italian blowing a two-set lead as the Australian, then still a teenager, roared back in an epic encounter.

But this time around it was Kyrgios' turn to falter from a dominant position as Seppi showed his fighting spirit to come back from two sets down to triumph 1-6 6-7 (1-7) 6-4 6-2 10-8 at a raucous Hisense Arena.

That marathon was sandwiched between much less dramatic victories for Federer and Murray, the former seeing off Noah Rubin 7-5 6-3 7-6 (7-3) while world number one and top seed Murray completed a 6-3 6-0 6-2 success over 19-year-old Andrey Rublev.

Federer will now meet Tomas Berdych, who overcame Ryan Harrison in straight sets, while Murray is slated to face Sam Querrey, if he overcomes an ankle injury sustained in the third set against Rublev.

It was a wonderful Wednesday for the Brits in the men's draw, as Dan Evans provided the shock of the day in coming from behind to oust seventh seed and 2014 US Open champion Marin Cilic 3-6 7-5 6-3 6-3.

RESILIENT SEPPI GAINS REVENGE

It was a stunning effort from Seppi, who had a partisan crowd as well as a fired-up Kyrgios to contend with.

At two sets down, the Italian looked to be heading home, but pulling one set back caused Kyrgios to slam his racket on the ground in anger - perhaps the first signs of what was to come.

Kyrgios' mood was not improved as Seppi levelled, but the Australian did manage to break back at 6-5 in the decider with Seppi serving for the match.

Seppi saved a match point with a sumptuous forehand down the line at 40-A 7-8, before a break in the next game set up the chance to serve out for the win, sealed with an ace to complete a stunning turnaround.

NO ISSUES FOR NISHIKORI, WAWRINKA FACES TRICKY TROICKI TIE

Standing in the way of that potential last-eight meeting between Murray and Federer could be Kei Nishikori.

The fifth seed had few problems in ousting Jeremy Chardy 6-3 6-4 6-3 to book a third-round meeting with Lukas Lacko. Should he overcome the Slovakian, Nishikori will meet Federer or Berdych.

Like Nishikori, fourth seed Wawrinka cruised through his second-round encounter, defeating Steve Johnson 6-3 6-4 6-4.

The Swiss, champion at Melbourne Park in 2014, will now take on Viktor Troicki (29). Wawrinka is likely to feel the fresher of the pair, with Troicki having prevailed in an epic with Paolo Lorenzi, 6-3 1-6 7-6 (7-3) 3-6 6-3.

SECOND BEST COMEBACK OF THE DAY: MISCHA ZVEREV

Before Seppi's heroics, Zverev was staring down the barrel of defeat on a couple of occasions during his five-set marathon with 19th seed John Isner.

Having lost the opening two sets on tie-breaks, world number 50 Zverev fought back to take the third but then found himself facing match point at 4-5 in the fourth.

He rescued the situation, forcing another tie-break, where he was made to save another match point at 6-7 behind. Three straight points levelled the match and, after wasting three match points of his own at 6-5 in the decider, the German broke to love to secure a 6-7 (4-7) 6-7 (4-7) 6-4 7-6 (9-7) 9-7 triumph.