Eighth seed Daria Kasatkina of Russia caused a huge upset when defeating world number one Caroline Wozniacki in the St. Petersburg Open quarter-finals on Friday.
Kasatkina beat the 2018 Australian Open champion 7-6(), 6-3 in a match lasting one hour and 32 minutes and will face French fourth seed Kristina Mladenovic in the semi-finals after she got past Czech Katerina Siniakova 6-4, 6-3.
In the first set, Wozniacki kicked off proceedings by holding serve, then in the fourth game broke to lead 3-1.
Kasatkina broke right back the next game and held to make it 3-3. The match proceeded on serve until the 11th game when Wozniacki dropped serve, but the Dane fought back and got the break back to make it 6-6 and take it to a tiebreaker.
The Russian was not to be denied and won the breaker 7-2 to claim the opening set 7-6.
In the second set, was always in control breaking Wozniacki’s serve twice to go on and serve out the set and match, saving a break point, to win it 6-3.
“She just won the Australian Open, and since I beat her, it means I was playing really well,” Kasatkina said on-court after the match. “I was just trying to play point-by-point and focus on the rally.”
In other quarter-final action, Petra Kvitova defeated No.2 seed Jelena Ostapenko 6-0, 6-2 to book her spot in the semi-final against fifth seed Julia Goerges after she downed teenage qualifier Elena Rybakina 6-3, 6-3.