June 9 (UPI) -- Greece's Maria Sakkari upset defending champion Iga Swiatek and Czech Barbora Krejcikova ended American teen Cori "Coco" Gauff's historic quest for a Grand Slam in two quarterfinal matches Wednesday at the French Open.
Krejcikova dispatched of Gauff in 1 hour, 50 minutes to advance to the semifinals in Paris. She fired five aces, 27 winners and converted four of six break points in the 7-6, 6-3 win on the clay surface of Court Philippe-Chatrier.
"I'm obviously disappointed that I wasn't able to close out the first set," Gauff told reporters. "To be honest, it's in the past, it already happened.
"After the match, my hitting partner told me this match will probably make me a champion in the future. I really do believe that."
Gauff, 17, totaled four aces, 25 winners and 41 unforced errors in the loss. She was the youngest woman in a Grand Slam quarterfinal since 2006 and the youngest American to reach that round since 1997.
"I don't realize what I have done," Krejcikova told the Tennis Channel. "I came here without a good start to a clay season. Now I'm here in the semifinals.
"I never imagined I would be here on this court, especially in singles. This is something that I never could have dreamed of."
Gauff raced out to a 3-0 lead in the first set, but Krejcikova responded with three-consecutive game victories. Gauff won the seventh and eighth games. Krejcikova won the ninth and 10th games.
Guaff bounced back with another game victory, but Krejcikova forced a tie break. The Czech converted three of her break point opportunities in the first-set triumph.
She carried that momentum into the second set, with five-consecutive game victories. Gauff rallied to win the next three games, but Krejcikova earned match point as the American's final return sailed wide and out of bounds.
"Coco is incredible," Krejcikova said. "When I was 17, I was playing ITFs [International Tennis Federation tournaments]. She is amazing."
Krejcikova will battle Sakkari in the semifinals at 10:15 a.m. EDT Thursday in Paris. The winner will face Tamara Zidansek or Anastasia Pavlyuchenkova in the final at 9 a.m. EDT Saturday at Roland Garros.
Sakkari and Swiatek took the court after the Gauff-Krejcikova match. Sakkari beat her Polish foe 6-4, 6-4 in one hour and 35 minutes to advance to her first career Grand Slam semifinal.
Sakkari fired five aces, 26 winners and won three of eight break points. Swiatek, who beat American Sofia Kenin in the 2020 French Open final, did not score an ace. She totaled 25 unforced errors and won just one of six break point opportunities.
Quarterfinal coverage will air from 5 a.m. to 5:30 p.m. EDT Wednesday on the Tennis Channel. The first round of semifinal coverage will air from 8 a.m. to 2 p.m. EDT Thursday on the Tennis Channel and from 11 a.m. to 2 p.m. EDT Thursday on NBC and NBCSN.