Melbourne: Roger Federer resumes his long-time rivalry with Tomas Berdych as giant-killers Chung Hyeon and Tennys Sandgren face off in an Australian Open quarter-final no one predicted on Wednesday.

Defending champion Federer, zeroing in on Grand Slam No. 20, lines up for his 26th career meeting with the big-serving Czech in his 14th appearance at an Australian Open last eight.

The 36-year-old Swiss legend holds a 19-6 lead over the 19th seeded Berdych dating back to their first meeting in 2004.

He is 4-0 over him in Melbourne, but Federer is taking no risks against a player who has beaten him twice at Grand Slams, at Wimbledon in 2010 and two years later at the US Open.

“We have had some good ones over the years going back all the way to the Olympic Games in Athens in 2004,” Federer said.

“I’m looking forward to play against him. He seems in good shape and I’m happy he’s over his back issues that he also had at the end of last year.”

Federer is shaping up for another potential final with world No. 1 Rafael Nadal, but first he must get past Berdych and then either surprise packages Chung or Sandgren.

The Swiss star is coming off an extraordinary 2017, when he won a fifth Australian Open title and a record eighth at Wimbledon and in his four wins so far looks in the mood to carry it on into 2018.

For Berdych playing Federer is “extremely tough”, but he says it’s another opportunity for him on the Grand Slam stage.

“I’m definitely going to go out there, try my best, try to play good tennis, and believe in myself that I can do it,” he said.

“I did it in the past and I did it in the slams, so I know how it is to beat him for the best-of-five sets. I’ll go out there and swing at some balls.”

Order of play

ROD LAVER ARENA

21-Angelique Kerber (GER) v 17-Madison Keys (USA)

Tennys Sandgren (USA) v Chung Hyeon (KOR)

1-Simona Halep (ROU) v 6-Karolina Pliskova (CZE)

2-Roger Federer (SUI) v 19-Tomas Berdych (CZE)