The Top 2 seeds had contrasting fortunes in the second round on Thursday at the BNP Paribas Warsaw Open.

World No.1 Iga Swiatek rolled in a 6-2, 6-2 win over American Claire Liu to book a spot in the quarterfinals, while No.2 seed Karolina Muchova 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. 

Swiatek improved to 4-0 against Liu all-time, and 3-0 this year, with a 1-hour and 37-minute victory. After the American held serve to start the match, Swiatek won five straight games. She also won the first four games of the second set.

Liu previously finished off a 7-6(3), 3-6, 6-2 win over Yuan Yue in the opening round Thursday morning -- a match that began Tuesday, and then was washed out Wednesday due to rain. The pair were knotted at 4-4 in the first set when play was suspended on Tuesday and at 7-6(3), 2-4 on Wednesday.

Swiatek has dropped just nine games in eight sets played against Liu this year. (They were scheduled to play in the second round at the Miami Open, but Swiatek withdrew.)

Swiatek will next face eighth-seeded Linda Noskova, as the teenager was a 6-3, 6-3 winner against Viktoria Hruncakova in her second-round match. Swiatek and Noskova are the only seeded players to reach the quarterfinals. 

More to come...