Petra Kvitova kept her winning streak going, while Angelique Kerber snapped Serena Williams'.
WTA Staff

CINCINNATI, OH, USA - A battle between the two best lefties in the world was set at the Western & Southern Open on Friday, as Angelique Kerber and Petra Kvitova out-hit some very big-hitting opponents in the quarterfinals.

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The No.5-seeded Kerber was the first to win, and pulled off the biggest surprise of the tournament, perhaps of the summer even, taking out No.2 seed Serena Williams, 64 64. Williams had won 36 of her last 37 matches, picking up titles at Charleston, Madrid, Wimbledon, Stanford and the Olympics - but Kerber was just too solid on the day, particularly on the big points - she converted both of her break point opportunities and fended off all four of Williams'.

"Today was one of the biggest wins of my career, and it's also amazing to be in the semis here," Kerber said. "I wasn't thinking about my opponent on the other side. My goal was just to give my best and hit the ball, move very well and get the balls back from her because they are so fast. I really had nothing to lose.

"I just tried to do my game plan and it worked."

Kerber had been saying she had nothing to lose before the match - she was asked to elaborate on that during her post-match press conference.

"Because Serena won Wimbledon, she won the Olympics, I mean, she won everything," Kerber replied. "She was the favorite, not me. It also feels better to tell yourself you have nothing to lose than you need to win. So I like it better."

Williams, who had won 19 matches in a row, talked about the loss afterwards. "I felt really good going out there today, much better than my other two matches here - false alarm," she said. "But she played really well today. She's getting a lot of balls back. I think she served more up the T than I expected. I really hope I can play her again in New York - I'll try to be ready for that one."

Williams will stick around to watch sister Venus' semifinal, however. "I'm a great cheerleader," she said. "I'll be happy to watch her and cheer for her. She's doing really well. She's playing much better than I am, moving better, serving well, moving up to short balls, hitting well - everything she's doing is great.

"I thought I was inspired, but I couldn't transfer it over to my game."

In the night match, the No.4-seeded Kvitova defeated No.17 seed Anastasia Pavlyuchenkova, 63 76(4), closing out a second set that saw zero breaks of serve with a clean tie-break, racing out to 4-1 and never looking back.

Kerber will now have to take on another winning streak - Kvitova has won eight matches in a row, 5-0 to win the title in Montréal and 3-0 so far in Cincy.

Kvitova and Kerber are tied in their head-to-head series. 1-1.

It was a banner day on Friday - the tournament set its single day attendance record with a combined 24,174 fans between the day and night sessions.