Wimbledon: Roger Federer Reaches Last-Eight, Sam Querrey Keeps Winning

Roger Federer reached his 14th Wimbledon quarter-final and tied Martina Navratilova's all-time Grand Slam record of 306 match wins on Monday. Meanwhile, Sam Querrey followed up his shock defeat of Novak Djokovic by beating Nicolas Mahut to reach his first Grand Slam last-eight.

The seven-time champion achieved his double landmark by seeing off Steve Johnson of the United States 6-2, 6-3, 7-5 in the fourth round on Centre Court.

Federer, the third seed, next takes on Croatia's Marin Cilic for a place in the semi-finals.

Cilic, the ninth seeded Croatian, progressed to his third Wimbledon quarter-final when Japanese fifth seed Kei Nishikori pulled out of their last-16 clash with a rib injury in the second set.

Federer has a 6-1 record over Cilic but the big Croatian stunned the 17-time major champion in the US Open semi-finals in 2014 on his way to his maiden Grand Slam title.

"He brushed me off the court in the US Open a few years ago and I hope to get him back," said Federer, who had former coach Stefan Edberg watching on from the player's box on Centre Court.

Johnson, the champion on grass at Nottingham this summer and playing in his first fourth round at a Slam, was comprehensively out-played in the first two sets.

He rallied to break the 34-year-old Federer in the fourth and sixth games of the third set but the former American college champion was reeled in on both occasions.

"Best of five matches are always tough," added Federer, whose 14th appearance in a Wimbledon quarter-final matches the mark of Jimmy Connors.

"I'm happy with how I played. It wasn't as easy as maybe it looked. Steve has picked up a lot of confidence in the last few weeks and he has a nice game for grass but I think I mixed it up well."

Federer has reached the last eight without dropping a set, easing to four successive wins on Centre Court.

"I would never have thought I would win the first four rounds in straight sets. I now need to play my best tennis."

Injury woe

Nishikori pulled out against Cilic suffering from a rib injury at 6-1, 5-1 down.

The 26-year-old confirmed it was the same injury which forced him out of the Halle tournament in the run-up to Wimbledon.

"It got worse after the second round. I couldn't compete today," said Nishikori.

Cilic had taken the first set in just 16 minutes, allowing Nishikori only seven points.

Querrey followed up his shock defeat of Novak Djokovic by beating Mahut 6-4, 7-6 (7/5), 6-4 to reach his first Grand Slam quarter-final.

Querrey, the 28th seed, is the first American in the last-eight at Wimbledon since Mardy Fish in 2011.

He will face either Canada's Milos Raonic or David Goffin of Belgium for a place in the semi-finals.