American qualifier Emma Navarro earned the first Top 10 win of her career after defeating No.3 seed Maria Sakkari 6-4, 0-6, 7-6(4) in the quarterfinals of the Cymbiotika San Diego Open. Navarro's win puts three Americans into the semifinals and sets up a showdown with Sofia Kenin on Friday. 

Collins, Kenin soar into San Diego semifinals

Navarro, 22, was the 2021 NCAA singles champion for the University of Virginia. San Diego is her second Hologic WTA Tour semifinal of the season, having made her first over the summer in Bad Homburg. 

"Really happy with the win today and with all the work that I've put in the last few months and my whole tennis career," Navarro said. "Happy with how I was able to finish that match. Definitely did not play my best tennis in the first couple of sets but definitely found myself in the third. 

Navarro has enjoyed a dominating week in San Diego. She entered the quarterfinals without losing a set across qualifying and then registered main-draw wins over Jasmine Paolini and Aliaksandra Sasnovich.

In the first meeting between the two, Sakkari broke first to lead 3-1 in the opening set. But the World No.9 struggled to neutralize Navarro's baseline power. The American stormed back to take the opening set, striking 12 winners to Sakkari's seven. 

Sakkari flipped the script in the second set by playing near-perfect tennis. She held Navarro to just one winner, zero break-point chances and nine points total in the 24-minute set.

Navarro halted Sakkari's momentum early in the third set, breaking first for a 3-2 lead. Sakkari broke back immediately, but Navarro's confidence was lifted and she rediscovered her range. The duo hurtled toward the tiebreak, where Navarro broke things open with a quick 4-0 lead and protected her lead from there.

Sakkari struck 26 winners and 24 unforced errors and broke serve on six of her 11 break chances. Navarro struck 27 winners to 34 unforced errors, breaking on four of her seven chances. 

"Playing in the U.S., it's my favorite place to play," Navarro said. "The support that they show us is really amazing. I really appreciate everyone coming out and showing love for the sport itself." 

Earlier, No.4 seed Barbora Krejcikova defeated Beatriz Haddad Maia 6-4, 6-3 to advance to her third semifinal of the season. The 2021 Roland Garros champion has not lost a set in San Diego. 

Krejcikova will face American Danielle Collins on Friday for a spot in her 11th Hologic WTA Tour singles final and first since winning the WTA 1000 in Dubai in February. 

"I never played her, I never practiced with her, so I have no idea what to expect," Krejcikova said. "But she's in the semis, she's won three matches, so I will definitely look at those matches."

Krejcikova raced to a 5-1 lead in the first set before Haddad Maia closed the gap to 5-4. But the Czech steeled herself well to serve out the game and take the one-set advantage.

"I think I was really calm," Krejcikova said. "I was really expecting that she would fight back and she would try to take every opportunity she could get. In those moments, I was focusing on myself and focusing on playing a good shot, and I'm happy that I did."

Krejcikova built on her advantage quickly in the second set, opening up a 3-0 lead. She protected that lead by controlling the baseline and closing out the win after 1 hour and 46 minutes to make her first semifinal since Birmingham.

Krejcikova finished the match with 24 winners to Haddad Maia's eight.