Serena Williams’ 19-match win streak was snapped by the No. 5 seed Angelique Kerber 6-4, 6-4 on Center Court at the Lindner Family Tennis Center.

 

The younger Williams sister, whose victories included titles at Wimbledon and Stanford and a gold medal in singles at the Olympics, never looked comfortable against the German’s counter-punching style.

 

Kerber is thrilled to advance to the final four. "I mean, today it was one of my biggest wins in my career, for sure," she said. "Yeah, it's amazing to be in the semis here."

 

Serena, who’s lost only four matches this year, said, "I felt really good going out there today, much better than my other two matches. False alarm."

 

She continued, "I really hope to play her again in New York and be ready for that one."

 

Venus Williams, meanwhile, notched her first semifinal appearance since 2010 with her win over defending US Open champion Samantha Stosur on the Grandstand. Venus needed over two hours and three sets to advance to her best showing in Cincinnati, winning 6-2, 6-7(2), 6-4.

 

For a spot into the final, she’ll face Li Na, who upset the tournament’s top seed Agnieszka Radwanska 6-1, 6-1. The 2010 Roland Garros champion finished as runner-up to Petra Kvitova, who was set to play later on Friday, in Montreal last week.

 

Looking ahead to her match against the top Chinese player, Venus said, "I know I'm going to have to bring my best game and try to up my first serve percentage if I can because that makes my life a lot easier, makes everybody's life easier in tennis." She continued, "That will be my main goal."

 

In doubles, Andrea Hlavackova and Lucie Hradecka, the runners-up at both Wimbledon and the Olympics to the Williams sisters, advanced to the final of the Western & Southern Open. They finished victorious in the final set tiebreak of their match against Darija Jurak and Katalin Marosi.