WTA roundup: Kostyuk, Boulter claim shock wins to setup San Diego final clash

Marta Kostyuk made a remarkable comeback in the opening set and emerged victorious in a thrilling tiebreaker. She then went on to secure a comfortable win in the semi-finals against the top-seeded Jessica Pegula at the San Diego Open on Saturday night.

With a final score of 7-6, 6-1, Kostyuk has earned herself a spot in the Sunday's final where she will face Katie Boulter. Boulter, currently ranked 49th in the world, displayed her dominance by defeating the third seed Emma Navarro with a convincing score of 6-3, 6-1.

Kostyuk was down 5-1 against Pegula in the first set but managed to win five consecutive games, breaking the top seed's serve twice. Pegula then rallied to even the match at 6-6.

Kostyuk, who previously came from behind to defeat fourth-seeded Anastasia Pavlyuchenkova of Russia in the quarter-final, took the lead in the tiebreaker after being tied 3-3. She secured the set on her second set point.

Boulter had an 88 per cent first-serve points won compared to Navarro's 62 per cent. Additionally, she dominated by winning 67 per cent of return points on the second serve.

In the Austin Open, sixth-seeded Xiyu Wang of China secured a two-set victory in a tiebreaker against top seed Anhelina Kalinina of Ukraine, with a score of 6-3, 7-6 in Austin, Texas.

Wang will face compatriot Yue Yuan, the eighth seed, in the final on Sunday after defeating Anna Karolina Schmiedlova 6-0, 6-3.

Wang took the first set over Kalinina after breaking away from a 3-3 tie. The second set was closely contested, with both players losing their serve twice, leading to a 6-6 tie.

Although Kalinina initially led the tiebreaker 3-2, Wang managed to win three consecutive points, including on Kalinina's serve, to take a 5-3 lead. Kalinina won the next point, but Wang secured the match by winning the next two points on serve.