Serena tosses racket, fights into third round at Wimbledon

World No. 1 Serena Williams rallied to reach the third round on Friday at Wimbledon, taking out her early frustration by tossing a racket that skidded into the lap of a cameraman.

The 34-year-old top seed beat fellow American Christina McHale 6-7 (7), 6-2, 6-4 after serving an ace to win the match, showing several fist pumps to the crowd on Centre Court.

Williams, the defending champion, lost her opening set in the second round and clearly wasn't pleased.

Williams held at set point while leading 5-4 but McHale then served a shot that was initially ruled out before being reversed after a video challenge. Williams lost the point when it was replayed.

After losing the set, Williams returned to her chair and slammed her racket against the ground several times before tossing it backward on the slick grass where it landed in the lap of a cameraman positioned in the photo pit.

On Saturday, Williams will face Germany's Annika Beck, who beat Aliaksandra Sasnovich of Belarus 6-2, 6-1.

Williams, a six-time Wimbledon champion, won the first three Grand Slams of 2015 but she has failed in her last three attempts to match Steffi Graf's Open era record of 22 major titles.

Five-time Wimbledon champion Venus Williams, Serena's older sister, made it through the rain and into the fourth round by overcoming 29th-seeded Darya Kasatkina of Russia 7-5, 4-6, 10-8.

Venus Williams' match on No. 1 Court was delayed four times by rain, including once with Williams holding a match point at 7-6 in the third set. When play resumed, Kasatkina saved the match point and held to 7-7.

Four games later, the eighth-seeded Williams broke to end the match, with Kasatkina hitting a forehand into the net on the final point.

On the men's side, Juan Martin del Potro of Argentina knocked out No. 4 seed Stan Wawrinka of Switzerland 3-6, 6-3, 7-6 (2), 6-3 to reach the third round.

Del Potro, the 2009 U.S. Open champion, was making his return to the lawn of the All England Club after a two-year absence. He has undergone three surgeries on his left wrist since 2014. In his most recent trip to Wimbledon in 2013, del Potro reached the semifinals.

"My hands (are) shaking," Del Potro said after walking off Centre Court to a loud ovation. "It's a great sensation for me because I'm playing tennis again and I feel alive."

Wawrinka, a two-time Grand Slam champion, is the highest-seeded man eliminated in the tournament.

"It's great for tennis to see him back," Wawrinka said of Del Potro. "He's a great guy, a really good player, big champion."

In the next round, del Potro will face No. 32 seed Lucas Pouille of France, who beat American Donald Young 6-4, 6-3, 6-3.

No. 10 seed Tomas Berdych of Czech Republic won 6-4, 6-1, 6-2 over Benjamin Becker of Germany, finishing right as rain interrupted play on the outer courts.