MELBOURNE (Reuters) - Czech Karolina Muchova recovered from a shaky start to defeat Belgian Elise Mertens 7-6(5) 7-5 on Monday and set up an Australian Open quarter-final against world number one Ash Barty.
Mertens, seeded 18th at Melbourne Park, came into the contest having won 30 matches since the women's tour restarted in August – the most by any player during that period.
She beat Muchova in straight sets at the end of last year in Ostrava in their only previous meeting and opened up a 4-0 lead in the first set with a double break of serves.
But 25th seed Muchova found her range at Margaret Court Arena and stormed back into the match to get back on level terms before claiming the opening set in a tiebreaker.
The 24-year-old got an early break in the second set but Mertens fought back to level at 2-2.
The players seemed headed for another tiebreaker but Muchova picked up the crucial break in the 11th game and converted her first match point when Mertens netted a return.
"It was a little bit slow start there from my side, but Elise played good," Muchova told reporters. "I think she didn't make any mistake and she was pushing me.
"Got back on the track at four-Love and kept fighting, kept playing every ball, trying to put it in and then go for my shots."
The match against Barty will be a second Grand Slam quarter-final for the Czech who reached the last eight at Wimbledon in 2019.
"It's a big challenge, and I definitely will have to bring my best tennis to compete with her and to have a good match out there," Muchova said.
(Reporting by Sudipto Ganguly in Mumbai; editing by Peter Rutherford and Ed Osmond)