Cincinnati Open WTA Round-Up | Elena Rybakina’s injury ends No. 1 bid as Swiatek and Pegula reach semis

The first half of the Cincinnati Open quarter-finals produced a dramatic day at the top of the women's draw, with Jessica Pegula surviving a three-set thriller against Amanda Anisimova before Iga Swiatek advanced in very different circumstances. The defending champion was handed a place in the semi-finals when Elena Rybakina was forced to retire with an apparent Achilles injury.

The results also reshape the tournament's ranking picture. Rybakina had arrived in Cincinnati with a clear opportunity to challenge Aryna Sabalenka for the No. 1 ranking after the Belarusian's shock defeat to Sara Bejlek. Instead, the Kazakh's retirement ends that immediate opportunity, while Swiatek continues her push after winning the Canadian Open last week.

Jessica Pegula survived a dramatic three-set battle against Amanda Anisimova to reach the Cincinnati semi-finals, recovering from a difficult second set and a physical scare to win 6-4, 2-6, 7-6. Pegula started the match strongly, taking the opening set and putting an end to Anisimova's hopes of maintaining her perfect record against the World No. 3.

Anisimova, however, completely changed the momentum in the second set. She broke early and moved 3-0 ahead before Pegula called for the physio and pointed toward her abdominal area. After the medical timeout, Anisimova immediately broke again to move 4-0 ahead, and although Pegula recovered one of the breaks, the American could not stop her opponent from forcing a deciding set.

The third set was another momentum battle. Pegula struck first and established a 3-0 advantage, but Anisimova refused to go away. The ninth seed gradually fought her way back and, after Pegula moved within one game of victory at 5-3, Anisimova won three consecutive games to take a 6-5 lead. Pegula then held under pressure to force the deciding tie-break.

Anisimova again looked capable of completing the comeback when she moved 4-3 ahead in the tie-break, but Pegula produced her best tennis when elimination was closest. She won four consecutive points to close out the victory and book a semi-final against Swiatek after more than two hours of play.

Iga Swiatek advanced to the Cincinnati semi-finals after Elena Rybakina was forced to retire while trailing 4-1 in the opening set. The Kazakh appeared to suffer an injury during her service game, stopping immediately after completing a serve and pointing toward the Achilles area before deciding that she could not continue.

The retirement was a particularly disappointing ending for Rybakina, who entered the quarter-final with enormous stakes beyond the match itself. After Aryna Sabalenka's shock loss to Sara Bejlek, Rybakina had a direct opportunity to move to No. 1 in the WTA rankings by reaching the Cincinnati final. She therefore needed to overcome Swiatek, the player she had faced in last week's Canadian Open final.

Swiatek had made the stronger start before the retirement, recovering from early pressure to establish the first break and move 4-1 ahead. The Pole had also entered the match on an eight-match winning streak after her Toronto title and was looking to continue her Cincinnati title defence.

Instead, the highly anticipated rematch ended after just five games. Swiatek moves on to face Pegula in the semi-finals, while Rybakina's immediate opportunity to take the No. 1 ranking disappears with her retirement.