Roger Federer beats Sam Groth to make last 16 at Wimbledon

Seven-time champion Roger Federer conquered big-serving Australian Sam Groth in four sets to reach the Wimbledon last 16.

The second seed may have appeared a little grumpy on Thursday over the organisers' strict clothing rules, but it was business as usual on Centre Court on Saturday as he overcame a couple of third set wobbles to ease through 6-4 6-4 6-7 (5-7) 6-2.

Federer's trademark backhand was in sublime form as he pushed the world No 69 into every corner to take the opening two sets with few problems.

It seemed a stroll to a straight sets victory for the 33-year-old Swiss but Groth, bidding to make the fourth round at a Grand Slam for the first time, pulled out a couple of firecrackers at crucial times to edge a third-set tie-break.

Federer stepped on the gas in the fourth set and after breaking Groth in the second game, was soon receiving a standing ovation to set up a clash with Spanish 20th seed Roberto Bautista Agut for a place in the quarter-finals.

Groth can at least take some consolation in firing a 147mph ace in the third game and now only lies behind Taylor Dent, whose 148mph serve in 2010 remains the tournament record.

Federer's performance was enjoyed by England's record Test wicket-taker Jimmy Anderson who topped a clutch of cricketing names on show, alongside ex-footballer Gary Lineker, England rugby boss Stuart Lancaster and captain Chris Robshaw.

"I am very happy," said Federer. "It has been a hot week the first week but thankfully I have had easy matches going through without too many long four or five setters.

"Now we are looking ahead and there are only big matches."

Former British and Irish Lions captain Brian O'Driscoll - rugby's most-capped player of all time - was also in the Royal Box, underlining Federer's undeniable imprint on the world's greatest tennis tournament.

"It's hard not to be impressed with Federer," said O'Driscoll. "His charisma, his grace and his movement around the court is just so special."