Tomas Berdych wasted no time in sealing a quarter-final spot in Melbourne on Monday, dispatching Italy's Fabio Fognini in straight sets.
Locked at 30-all and trying to stay on serve in the seventh game, the 30-year-old was called for a foot fault on his first serve.
The defending champion did not require his dazzling best against 80th-ranked Hungarian Marton Fucsovics in his first match scheduled during the day session but still emerged a comfortable 6-4 7-6 (3) 6-2 victor.
"I'm definitely going to go out there, try my best, try to play good tennis, and believe myself that I can do it".
"I did it in the past, and also, I did it in the slams, so I know how it is to beat him for the best-of-five sets".
Pouncing on Berdych's second serve, he prowled along the baseline and broke back for 2-2 when the Czech netted after a 24-shot rally, before holding with a brilliant running victor.
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'But obviously it's extremely tough opponent, and, yeah, just to go out there and swing some balls'.
Federer rifled a running forehand pass to earn three set points and again finished the set at the net, with a smash.
"So if we're going to go play tomorrow again, it would be probably a different match", Berdych said. He had some back issues late a year ago and that slowed him down, I think.
"I'm enjoying it a lot".
"I'm glad to be back in the shape that I am right now, which is finally healthy and that makes the difference", said former world number four Berdych, whose lowly ranking resulted from an injury-plagued 2017.
"He hung with me for a long time. Yeah, the results are coming with that", he added. In 2014, he fell in the semi-finals to eventual champion Stan Wawrinka; in 2015, Berdych lost to Andy Murray.