Reigning Wimbledon champion Angelique Kerber reached the Indian Wells semi-finals for the third time with her 7-6 (7/3), 6-3 win over Venus Williams in a battle of former world number ones.

Kerber dominated the tiebreaker to grab a hard-fought first set that featured four breaks of serve.

She had to fight for the lone break of the second set as Williams saved four break points to hold for 2-2 and saved four more in the sixth game before Kerber finally converted one for a 4-2 lead that would stand up the rest of the way.

Williams never got her big serve going, producing just one ace. The 38-year-old veteran did her best to catch Kerber out with crafty changes of pace, but the German was able to adjust.

“I think every body saw that Venus is really a player with a lot of experience,” Kerber said. “She played really tricky – in the good way – it was really hard for me to play my game.

“I was really trying in the first set especially to find my rhythm but it was not so easy. I’m happy that I won the first set and then could move in and play a little bit better.”

Friday night’s other semi-final had already been set with 18-year-old Canadian wildcard Bianca Andreescu due to take on world number six Elina Svitolina of Ukraine.

Bencic powers on

Resurgent Swiss Belinda Bencic toppled another top-10 player Thursday, downing fifth-ranked Karolina Pliskova to set up a semi-final showdown against Kerber.

Bencic, a former world number seven whose ranking slumped as injuries stalled her career, showed no sign of a let-down after her fourth-round victory over world number one and defending champion Naomi Osaka, out-lasted Czech Pliskova 6-3, 4-6, 6-3.

She stretched her WTA match winning streak to 12 – six of those wins coming against top-10 players with No. 8 Kerber coming up.

“Of course I’m very confident,” said Bencic, who rose to 23 in the world with her first WTA title in four years at Dubai last month and will crack the top 10 by virtue of reaching the semis here.

“I’m not putting pressure on myself even now,” the 22-year-old said. “I’m just playing. The less I think on the court the better it is.

“When you’re confident you can just trust your instincts and you don’t have to think about it at all. I’m definitely playing how I feel it, and it’s going so well I’m not planning on changing that.”

Pliskova launched her season with a 12th career title in Brisbane, and shocked Serena Williams to reach the Australian Open semi-finals.

After dropping the first set she came back strong in the second, winning the first four games as she forced a decisive third set, although not before Bencic saved four set points.

Close games marked the start of the third, with Pliskova fighting off four break points in a game that went to eight deuces to hold for 2-2.

But Bencic held her next two service games with authority and broke for a 5-3 lead, finally sealing the match with a serve that was too much for Pliskova.