Britain's Johanna Konta beat Venus Williams 6-4, 7-5 in a grueling battle Thursday to reach the WTA Miami Open final, where she will face Caroline Wozniacki of Denmark.
The Australian-born 25-year-old broke Williams in the first game and played aggressively throughout the opening set.
Williams fought back strongly in the second set, breaking to go up 3-1. But Konta broke back immediately and again for a 5-4 lead that allowed her to serve for the match.
The American took advantage of some nervy play from the 10th-seed to break back, but Williams was unable to hold serve and that gave Konta a second chance to wrap up the contest, which she did after more than two hours.
Konta said she expects a big challenge ahead in order to capture her second title of the year after a Sydney crown.
"I am going to have a tough battle on my hands," Konta said. "Caroline makes you work."
Wozniacki booked her place in the final after rallying to defeat Czech second seed Karolina Pliskova 5-7, 6-1, 6-1.
Pliskova, who won titles this year at Doha and Brisbane, also fell in the semi-final stage at Indian Wells two weeks ago.
The Czech broke Wozniacki in the first game of the match but the Dane fought back and at 5-4 had three set points, which Pliskova manage to deny her.
Wozniacki then double faulted to give the Czech a break point, which she took before serving out for the set.
But former world number one Wozniacki, wearing down Pliskova with her solid defense, ran out a comfortable winner in the following two sets to earn a third final appearance of the year.
"I'm not sure how I managed to do that," Wozniacki said. "It is tough when you lose that first set -- especially having set points, it hits you a little bit. But I got a good start to the second set and that got me going, got me grinding."
In her two finals this year, both in February, Wozniacki was beaten by Pliskova at Doha and by Ukrainian Elina Svitolina at Dubai.
Pliskova, who began the year with a title at Brisbane, was philosophical about her second semi-final loss of the month.
"I'm definitely positive," she said. "I've won a lot of matches this year. I can't be too disappointed but obviously I am disappointed to lose two semi-finals especially when I think I could have won both matches.
"Obviously I think I could have done a bit more this year but then again I have never had a start to a season like this."