Angelique Kerber knew what it would be like to play Roberta Vinci in their U.S. Open quarterfinal. She knew Vinci would work her around the court, that she could unleash a hail of drop shots and her slice backhand is a sword disguised as a feather.

Kerber had no trouble moving around the court, was only occasionally perplexed by the drop shot, and the slice backhands never cut deeply into her game. Thus, she played her way into the Open semifinals for the first time since 2011 with a 7-5, 6-0 win Tuesday on Arthur Ashe Stadium Court.

Despite being broken three times in the first set, Kerber maintained the necessary patience to overcome the veteran Vinci, whose run to the Open final last year included a shocking victory over Serena Williams in the semis.

“I think the key of the match was the first set. I mean, it was really close and tough,” Kerber said. “It’s always difficult to play against Roberta. I mean, she’s a tough opponent with her slice. Yeah, I was trying to staying in the match and not thinking that I’m the break down. Just going for it. I think that was my key also like for the first set to being a little bit more relax and [be] not too negative, actually.”

She broke Vinci to win the first set, the break coming on a double fault when Vinci was called for a foot fault. Vinci gave the base linesman a thumbs up on the way to her chair.

“Bad luck for the first set. I had so many chances,” Vinci said. “Probably I was playing better than her the first set. But she’s a great player. She miss maybe two or three balls and she run a lot. She’s in confidence. So I lost the first set, and then the second set she started to play better than the first set. I was a little bit down.”

Kerber made 22 unforced errors in the first set, three in the second. Vinci helped by serving poorly, getting only 40 percent of her first serves in play. Kerber served 77 percent on her first serve.

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Kerber was 23 years old when she made the semifinals here. Much has matured with her personality and her game since. She beat Serena Williams in the final of the Australian Open in January to capture her first Grand Slam and lost to Williams in the Wimbledon final. This will be the first time in her career that she has made three Grand Slam semifinals in a season.

“ I think it’s changed a little bit,” Kerber said. “For me, I’m going out on Arthur Ashe, on the stadium, and playing against top player, as well. I know that I can beat everybody, and this is what gives me also a lot of confidence and motivation for going out there and playing with a lot of emotion.”