Andy Murray booked his place in the quarter-finals of Wimbledon without dropping a set so far as he saw off the challenge of towering South African Kevin Anderson.

After a flawless first week, this was certainly the defending champion's toughest test but he passed it with flying colours, saving a set point in the third-set tie-break to win 6-4 6-3 7-6 (8/6).

Murray, who is likely to next meet Queen's champion Grigor Dimitrov, had a minor blip early in the second set after the roof was closed but quickly adjusted to the indoor conditions.

Murray said: "When it was outdoors, I played very well, I was in a good position.

"When we came back indoors he started to strike the ball a bit better, he started serving better and I was dropping the ball a little bit shorter than I was in the first set and a half so I had to do a bit more running.

"I got a bit tentative, but it was a good win because he was playing very well at the end, making it very tough for me."

Novak Djokovic marched into the quarter-finals with an intimidating show of strength to floor Jo-Wilfried Tsonga in straight sets.

Tournament favourite Djokovic demonstrated his title credentials with a commanding 6-3 6-4 7-6 (7/5) dismissal of the French 14th seed.

Djokovic will tackle Marin Cilic in the last eight, after the Croatian 26th seed eased past Jeremy Chardy in straight sets.

Six-time grand slam winner Djokovic is bidding to avenge last year's straight-sets defeat to Andy Murray in the final, with his comfortable progression on Monday underlining his increasing resolve.

Tsonga admitted heading into his Djokovic showdown that only increased clashes with tennis' big four will help him crack the sport's highest echelons.

The Le Mans native was never in the races in the first two sets though, and failed to convert two break points when the score was locked at 4-4 in the final set.

Djokovic let out a visceral roar after fending off those two break points to hold his serve, before the third set moved into a tie-break.

On match point the Serbian world number two whipped a brilliant backhand cross-court winning service return - before outstretching his arms and nodding his head in coach Boris Becker's direction.

The ball was called out, but Hawk-Eye showed it had touched the line, and Djokovic was through.

Stanislas Wawrinka shrugged off his potential logjam with a straight-sets victory over Denis Istomin.

The Swiss number five seed saw off world number 45 Istomin 6-3 6-3 6-4 to reach Wimbledon's fourth round for the first time in five years.

Wawrinka could face five matches in seven days in order to reach the All England Club final after Saturday's rain delays skewed the men's schedule.

Coach Magnus Norman labelled Wawrinka's fixture pile-up "not really human", after rain shunted the fourth-round ties in the bottom half of the men's draw back a day.

Japan's Kei Nishikori completed his truncated five-set victory over Italian Simone Bolelli to kick-start Monday's proceedings.

The 10th seed wound up his third-round clash 3-6 6-3 4-6 7-6 (7/4) 6-4, held over after Saturday's rain delays.

Nishikori will now face Canada's eighth seed Milos Raonic in the fourth round.