Top-seeded Marin Cilic escaped a second-round scare on Thursday, but fourth-seeded American Sam Querrey wasn't as fortunate at the $1.212 million U.S. National Indoor Tennis Championships.
Cilic saved three match points and needed two hours, 36 minutes to get by Dutchman Igor Sijsling 7-6 (7-2), 3-6, 7-6 (9-7) at The Racquet Club of Memphis. It was the Croatian's eighth straight victory following a five-set loss to Andreas Seppi in the third round of the Australian Open last month.
Querrey, who titled here in 2010, had 15 aces in his match against Marinko Matosevic, but the Australian earned four breaks of serve and took a 3-6, 6-4, 7-5 decision to reach the quarterfinals.
Three-time Memphis champion Tommy Haas of Germany withdrew from his match against Feliciano Lopez of Spain because of an illness.
Two ranked players each expelled Americans, as fifth-seeded Kei Nishikori of Japan rolled to a 6-3, 6-3 win over Donald Young, and seventh-seeded Alexandr Dolgopolov of Ukraine defeated Rhyne Williams, 6-4, 4-6, 6-4.
Jack Sock advanced with a 7-5, 6-4 win over his doubles partner this week and fellow American James Blake. Since finishing as runner-up 11 years ago, Blake has not won back-to-back matches in this tournament.
Also on Day 4, American journeyman Michael Russell topped Pole Lukasz Kubot 6-2, 6-4, and Uzbekistan's Denis Istomin drilled fading former world No. 1 and two-time Grand Slam titlist Lleyton Hewitt 6-1, 6-2.
The 2013 Memphis champ will claim $291,800.