Czech Karolina Muchova recovered from a shaky start to defeat Belgian Elise Mertens 7-6(5) 7-5 and reach the last eight of the Australian Open on Monday. Mertens, seeded 18th at Melbourne Park, had defeated Muchova in straight sets at the end of last year in Ostrava in their only previous meeting and was cruising at 4-0 in the first set.
But 25th seed Muchova then found her range at Margaret Court Arena and soon got back on level terms before taking the opener in the tiebreaker.
The 24-year-old picked up the crucial break in the 11th game of the second set and converted her first match point when Mertens found the net on a return.
The Czech will next meet top-ranked Australian Ash Barty or American Shelby Rogers.