Roger Federer remained on course to defending his Australian Open title and landing a 20th Grand Slam title by defeating Tomas Berdych for the third consecutive year to reach the semi-finals.
Federer was a straight-sets winner over his Czech rival in the quarter-finals in 2016 and the third round last year, and he was forced to overcame an early wobble to win 7-6 (7-1) 6-3 6-4 on Rod Laver Arena and book date with the unseeded Chung on Friday.
The defending champion lost the opening three games against Berdych and trailed 5-3 in the first set.
Federer was unhappy with a Hawk-Eye challenge that was not shown on screen because of a technical malfunction and had a long and testy conversation with the umpire. But being fired up helped the 36-year-old, who saved a set point, broke back and then saved a second set point in the following game.
He was rarely troubled thereafter as he raced through the tie-break and it soon became a familiar story for Berdych in the end as the Swiss legend ran away with the match to reach his 14th Melbourne semi-final in the last 15 years.
He said of the first set: “I hung around, had to get a bit lucky, a bit angry, a bit frustrated maybe but I actually thought the call was good anyway. It’s all good. I’m very happy I got out of that first set, it ended up being the key to the match. Tomas played great. I stole that one a little bit.”
It was different last year, when Federer was coming back from a long break and played a series of lengthy matches.
“In a way I prefer it this way because I wake up in the morning walking normally. The pain’s good sometimes and those five-setters are so worthwhile, you take them with you for a lifetime.
“That match against Berdych showed me I could do it, maybe. My expectations are much different this year. I won a couple of slams last year. Last time here, I hadn’t won one for four years.”
It was the eighth time Federer had beaten Berdych out of 10 Slam meetings and a ninth consecutive victory overall against the Czech.
Federer’s career statistics continue to get more remarkable, with 2015 the only time since 2003 that he has failed to reach the last four in Melbourne.