STANFORD, CA, USA - No.3 seed Madison Keys knocked out reigning Wimbledon champion Garbiñe Muguruza in straight sets to reach the final at the Bank of the West Classic.

Keys needed just under an hour to seal the 6-3, 6-2 victory, snapping the Spaniard’s nine-match winning streak.

“I would say this is my best performance of the year, as far as playing well from start to finish,” Keys said in her post-match press conference.

“Everything was just really solid, I wasn’t going for crazy winners or doing anything amazing. It was just solid smart tennis.”

Top seeded Muguruza had cut an imperious path to the Stanford semifinals, eager to get back on court after her Grand Slam success and avoid the disappointing slump she faced after her 2016 French Open victory.

She had not dropped serve all week long, but against Keys she faltered in her first service game after the pair traded breaks to start the match.

A few tentative games later - during which both big-hitters put each other through a thorough baseline examination - Keys took a late break of serve, rocketing ahead to reel off 12 of the last 14 points and claim the opening set.

Muguruza never managed to find her range off the ground after that, and Keys was not keen to give her any chances. The American broke three more times and, after just 58 minutes, took her spot in the Stanford final.

“I think the key of Keys today was the serve,” Muguruza joked in her post-match press conference. “She served very well today, I think she played well. And I did a few mistakes in the important moments when it didn’t go my way.

“I’m happy that I did well here and reached [the] semifinals. I felt great this week - maybe today a little bit worse - but I’m very happy that I came [to Stanford] and I think it’s a great start to my American swing.”

Keys will be pleased with the victory after a difficult year battling injury - the American missed the opening two months of the season after undergoing left wrist surgery during the off season, an injury which flared up again after Stuttgart.

“To be honest, just being in the final and having some really good matches in and feeling that I’m on a good path right now has been the best part of this whole tournament,” she said.

“Win or lose tomorrow, that’s obviously a huge thing for me. But I do want to win though, so I’m going to do everything that I can to do that.”

Through to her first final of 2017, Keys will face off against countrywoman CoCo Vandeweghe, who took down fellow American CiCi Bellis earlier in the day.