Serena Williams was just one point away from a comeback victory in the Australian Open quarterfinals Wednesday when she twisted her left ankle and subsequently lost to Czech star Karolina Pliskova. After a promising start, Williams squandered four match points along the way to dropping the last six games of a 6-4, 4-6, 7-5 loss to No. 7 seed Pliskova at Melbourne Park. Instead of Williams moving one match closer to an eighth championship at the Australian Open—and record-tying 24th Grand Slam title overall—Pliskova will advance to the semifinals in the pursuit of her first major trophy. “I was almost in the locker room,” said Pliskova, who trailed 5-1 in the third set, “but now I’m standing here as the winner.” She will face No. 4-seeded Naomi Osaka, who beat No. 6 Elina Svitolina 6-4, 6-1 earlier Wednesday.