Kerber reaches semis in Cincinnati, keeps Williams in sight

MASON, Ohio (AP) Angelique Kerber has Serena Williams within arm's reach, and she's trying not to think about it.

Kerber advanced to the Western & Southern Open semifinals Friday, staying on track to overtake Williams at No. 1. She overcame a sloppy first set and beat Carla Suarez Navarro 4-6, 6-3, 6-0.

If Kerber wins the tournament, she'll move ahead of Williams in next week's WTA rankings. Williams has been No. 1 for 183 consecutive weeks, the second-longest such streak. She is the two-time defending champion but withdrew because of a sore shoulder.

And now, she could wind up getting passed by Kerber, who doesn't want to put any more pressure on herself.

''Of course, everybody is asking me this question,'' Kerber said. ''And yeah, let's see what happens in the next weeks or next days. When the time is ready, maybe I can reach the No. 1 (ranking). Still, it's a long way. It's closer than a few days ago when I sat here.''

In the men's bracket, Andy Murray struggled with a stiff back and gritted out a 6-4, 6-4 victory over Bernard Tomic to reach the semifinals and extend his successful summer, which includes his second Wimbledon title and another Olympic gold medal. He has won his last 21 matches, a career high.

''I think it's just fatigue, really,'' Murray said. ''I have played a lot of the matches in a short space of time, and also there's been a change of surface as well. It does put a little bit more stress on the joints, the hard courts. Yeah, just accepting it for what it is. I'll be fine. I just need to work through it and accept it.''

Murray is the only player in the tournament who has won a Cincinnati championship, taking it in 2008 and 2011.

Kerber has reached the finals in Cincinnati once before, losing to Li Na in 2012. She was in trouble after a sluggish opening set on Friday - 17 unforced errors - but took control early in the second set. She had only seven unforced errors in the final set.

Kerber will play third-seeded Simona Halep, who beat Agnieszka Radwanska for her 13th straight match victory. Kerber beat Halep in the quarterfinals at Wimbledon. Halep has reached the finals in Cincinnati once, losing to Williams in 2015.

Karolina Pliskova also advanced with a 6-3, 4-6, 6-2 win over Svetlana Kuznetsova. She'll face Garbine Muguruza, who beat qualifier Timea Babos in straight sets.

The men's bracket was wide open with the top players missing. Top-ranked Novak Djokovic and defending champion Roger Federer skipped the tournament because of injuries. Rafael Nadal is still getting back into playing shape after a wrist injury cost him two months and was knocked out of the tournament on Thursday.

Murray is the only member of the Big Four still left, but he's running on fumes. He won the gold medal at the Olympics in Rio de Janeiro on Sunday, flew to Cincinnati and reached the quarterfinals despite a worn-down body and a nagging head cold.

On Friday, he reached for his stiff lower back after chasing a ball in the first game of the match and favored it throughout the set. He moved much better around the court in the second set, broke Tomic to go up 5-4, and served it out.

Tomic fell to 0-17 against players ranked in the top four. He's 0-5 career against Murray, failing to win a set.

Murray will face Milos Raonic in the semifinals. One of the Big Four has won 54 of the last 58 Masters events.

The wide-open tournament provides a chance for someone like the unseeded Grigor Dimitrov to win a Masters title. Dimitrov reached the semifinals of a Masters event for the third time, beating top American Steve Johnson 7-6 (8), 6-2.

''I mean, I'm hoping I'm going to be playing here on Sunday,'' Dimitrov said.

Despite the loss, Johnson will become the top American in the ATP rankings next week. John Isner has held the top spot since July 29, 2013.

Dimitrov will play Marin Cilic, who reached his first Masters semifinal when 19-year-old Borna Coric retired after losing the first set. Coric played the set with both knees taped.

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