Serena Williams edged out Alison Riske in a hard-fought quarter-final at Wimbledon on Tuesday to reach the competition's final four.
The seven-time champion will go on to face Czech Barbora Strycova for a place in Saturday's women's final. Strycova came through her quarter-final against Great Britain's Johanna Konta in straight sets.
Meanwhile, Simona Halep overcame an early scare from Zhang Shuai to progress to the last four. The seventh seed will play Elina Svitolina in the semi-finals following her victory over Karolina Muchova.
Women's Singles Results
(7) Simona Halep bt. Zhang Shuai, 7-6 (4), 6-1
(11) Serena Williams bt. Alison Riske, 6-4, 4-6, 6-3
Barbora Strycova bt. (19) Johanna Konta 7-6 (5) 6-1
(8) Elina Svitolina bt. Karolina Muchova 7-5, 6-4
Riske's meeting with Williams was their first singles match against one another. It was also the former's first Grand Slam quarter-final, whereas the latter is in pursuit of her 24th major singles title.
Williams was twice a break down in the opening set, but she battled back to take it 6-4.
A strong start from Riske made it a competitive contest from the outset, and she fended off some strong serving from Williams to draw first blood, per SportsLine's Mike McClure:
The 29-year-old responded immediately when Williams levelled proceedings at 3-3, but after the seven-time Wimbledon champion broke back a second time for 4-4, she used that momentum to take the set.
Both players found breaks more difficult to come by in the second set, and Riske kept Williams on her toes with some neat shot variation, catching out her illustrious opponent with a well-executed drop shot.
The unseeded player claimed the decisive break in the ninth game with a delightful half-volley at the net.
In contrast to the second, a flurry of early breaks kicked off the third set with two apiece for Riske and Williams.
A double-fault proved costly for the former, and that was all the encouragement Williams needed to see out the match.
Zhang flew out of the traps against Halep, and some powerful hitting earned her a break in the Romanian's first service game as she raced to a 4-1 lead.
The turning point came in the sixth game, though, when Halep saved four break points for a vital hold. A double-fault from Zhang then allowed the No. 7 seed to break back.
Tennis writer Carole Bouchard noted how the Chinese player's profligacy proved costly:
After edging out Zhang in a first-set tiebreaker, Halep carried her momentum into the second set, rattling through the contest to a comfortable win:
Halep will play Svitolina in the semi-final, her second time in Wimbledon's final four after a run to the semis in 2014.
Meanwhile, Svitolina is into the last four of a Grand Slam for the first time in her career after seeing off Czech star Muchova in two hard-fought sets.
The win means Svitolina makes history at Wimbledon:
Muchova dropped her serve at the start of the match but responded well by coming back to take a 4-1 lead in the opening set.
Yet Svitolina battled back and clinched her third break after a lengthy game at 5-5 to gain a crucial advantage that allowed her to go on and seal the first set in 48 minutes.
The 24-year-old served for a place in the semi-final at 5-2, but Muchova managed to break and then hold serve to put pressure on the eighth seed.
However, Svitolina made no mistake at the second opportunity, finishing off with a service winner to secure a semi-final spot.
Home favourite Konta's hopes of winning a first Grand Slam are over after she was beaten by 33-year-old Strycova in an hour and 37 minutes.
Konta took a 4-1 lead and looked in good shape in the opening set, but a number of unforced errors and some aggressive play from Strycova allowed the Czech to level and then clinch the opener on a tiebreak:
More errors followed from Konta in the second set, which allowed Strycova to run away with the match and cruise to victory.
The defeat to a lower-ranked opponent in a Grand Slam quarter-final will feel like another missed opportunity for Konta, while Strycova is now in uncharted territory:
The win means the Czech star is just one step away from a first major final, but she will be the underdog again when she meets Williams on Thursday.