Roger Federer on Sunday continued his remarkable return from injury by beating Kei Nishikori in five sets to reach his 13th Australian Open quarter-final.
The 35-year-old beat fifth seed Nishikori 6-7 (4-7) 6-4 6-1 4-6 6-3 to keep alive his hopes of an 18th Grand Slam and fifth Australian Open title.
Federer, seeded 17th, is playing his first competitive event since Wimbledon six months ago following a knee injury.
He will play Mischa Zverev, conqueror of Andy Murray, in the last eight.
Third seed, Stan Wawrinka, defeated Andreas Seppi 7-6 (7-2) 7-6 (7-4) 7-6 (7-4) and goes on to face Jo-Wilfried Tsonga, who beat Dan Evans 6-7 (4-7) 6-2 6-4 6-4.
After dropping his opening two service games, Federer found the range that had seen him hammer Tomas Berdych in the previous round, giving Nishikori a torrid time.
“I wasn’t playing badly in the first set; it’s a quick court and things happen fast. It was about staying calm at 4-0.
“I thought it can’t get any worse from there. It was hard not to win that first set after all the effort but it paid off in the end. This is a huge win for me in my career.
“It was a great match and a joy to be part of it,” Federer said.
The News Agency of Nigeria reports that Federer won the Australian Open in 2004, 2006, 2007 and 2010.
From 5-1 down, the Swiss roared back, almost taking the set, before losing out in a tie-break and clinching the second set with a solitary break.
The third disappeared in a flash as Federer took apart the Nishikori serve, winning every point on the Japanese player’s second serve.
He went close to breaking through again early in the fourth set.
Nishikori, 27, held on under huge pressure and forced a decider but it was Federer who proved the stronger, racing into a 3-0 lead and closing it to the delight of most of those on Rod Laver Arena.
NAN reports that Nishikori has never been past the quarter-finals in Melbourne
Federer played just seven events in 2016 after injuring his knee the day after his Australian Open semi-final and having arthroscopic knee surgery.
He dropped out of the world’s top 10 for the first time in 734 weeks last November to arrive in Melbourne, ranked 17th, his lowest position since May 2001.
The Swiss is the oldest man to reach a Grand Slam quarter-final since the 39 year-old Jimmy Connors at the 1991 US Open.
The Australia open 2017, which started on January16, is expected to end on January 29.