Serena's 300th Slam win

Serena Williams needed just 51 minutes to clinch the 300th Grand Slam win of her career on Sunday as the defending champion made the Wimbledon last 16.

The 34-year-old American brushed aside Germany's world number 43 Annika Beck 6-3, 6-0 on the back of 25 winners and seven aces and goes on to face long-time Russian rival Svetlana Kuznetsova.

"I thought it was good. I still want to get out to a little bit of a faster start but I was really focused and calm," said Williams, who is just six wins short of Martina Navratilova's Open Era record of 306 Slam wins.

Williams has now won 82 matches at Wimbledon as she remains on course to equal Steffi Graf's Open Era record of 22 Grand Slam titles with her seventh Wimbledon crown.

Williams took the starring role as play was held on the middle Sunday for only the fourth time in Wimbledon history, and the first time since 2004, as organisers tried to clear the backlog caused by days of rain.

Two-time Grand Slam champion Kuznetsova also reached the fourth round for the first time since 2008 despite becoming involved in a row with the umpire over coaching.

The 31-year-old 13th seed battled from 2-5 down in the final set to defeat US 18th seed Sloane Stephens 6-7 (1/7), 6-2, 8-6.

Nick Kyrgios booked a clash with Andy Murray for a place in the quarterfinals after downing Feliciano Lopez in the third round.

The Australian 15th seed won 6-3, 6-7 (2/7), 6-3, 6-4 on Court One in a match that was tied at one set all when bad light stopped play on Saturday.

Kyrgios will face second seed and 2013 champion Murray in the fourth round on Monday. The British star is the top seed left in the draw after world number one Novak Djokovic was knocked out by Sam Querrey in a shock result Saturday.

But Kyrgios fancies his chances nonetheless.

"I definitely have the tools to do it, but saying that, he's probably one of the best players in the world and he's probably the favourite at the moment since Novak is out," the Australian said.

Jo-Wilfried Tsonga reached the Wimbledon last 16 on Sunday by downing US marathon man John Isner 6-7 (3/7), 3-6, 7-6 (7/5), 6-2, 19-17.

French 12th seed Tsonga, a semifinalist in 2011 and 2012, saved a match point in the 32nd game of the final set.

The last set alone lasted more than two hours. Isner, the 18th seed, famously won the longest tennis match ever played when he beat another Frenchman, Nicolas Mahut. 70-68 in the final set at Wimbledon in the first round in 2010.

The five-setter, stretched over three days, lasted 11 hours and five minutes.

Isner had led Tsonga by two sets to one when play was halted at sunset on Saturday.

The American ended the four-hour, 25-minute tie with 38 aces, 101 winners and 53 unforced errors.

Czech 10th seed Tomas Berdych appreciated the history of the rare middle Sunday play at Wimbledon as much as he savoured his 6-4 6-4 4-6 6-1 victory over talented teenager Alexander Zverev.