MELBOURNE, Feb 17 (Reuters) - Karolina Muchova said she was so dizzy she thought she was going to faint during her Australian Open quarter-final against Ash Barty on Wednesday before a lengthy medical timeout helped her regain her composure to turn the tables on the world number one.
Home favourite and top seed Barty was leading by a set and a break when Muchova called for the timeout at a steamy Rod Laver Arena.
"I was feeling kind of dizzy at some point, like really lost and almost fainting. I just asked for help," said Muchova, who won 1-6 6-3 6-2 to reach the semi-finals.
"They just checked my (blood) pressure because I was a bit lost, you know? I was spinning. So they cooled me down a bit with ice, and it helped me."
Play resumed nine minutes later and a recharged Muchova found her feet almost immediately, breaking Barty's serve for the first time in the match.
With shortened rallies and bold shot-making, Muchova went on to break her opponent twice in the final set to reach a Grand Slam semi for the first time.
"Played a bit faster, going to the net. I think that was the key by the end," the Czech said.
Muchova's comeback was her third come-from-behind win of the campaign. She reeled off the last seven games from 5-0 down in the second set to win in the 7-5 7-5 against compatriot Karolina Pliskova.
Against Elise Mertens, Muchova clawed back from a 4-0 deficit in the opening set, while against Barty, she claimed 12 of the final 15 games.
"Honestly ... I'm trying to start good," Muchova said. "It seems a bit like these slow starts for me are a tradition I can't get rid of here."
Muchova will next face American Jennifer Brady for a place in the final.