WARSAW: Iga Swiatek eased into the quarter-finals of her home WTA tournament on Thursday while Karolina Muchova, the woman she defeated in the French Open final, crashed out after squandering four match points.

World number one Swiatek swept aside Claire Liu of the United States 6-2, 6-2.

It was Swiatek’s fourth win in four meetings against Liu, three of which have come this year.

Swiatek gets off to perfect start in Italian Open

Second seed Muchova, ranked 18 in the world, was upset by Slovak qualifier Rebecca Sramkova 7-5, 3-6, 7-5 after failing to convert on a 5-1 lead and four match points in the third set.

Muchova has struggled since finishing runner-up to Swiatek at Roland Garros.

She was knocked out in the first round at Wimbledon to world number 103 Jule Niemeier of Germany.