Defending champion Marin Cilic advanced to the third round at Queen's Club with a 6-3, 6-4 win over fellow Croat Ivan Dodig on Wednesday.
The No. 5-seeded Cilic was never under pressure and Dodig failed to earn a break point.
Cilic won the title last year when David Nalbandian was defaulted for violent conduct after he kicked an advertising sign and injured a line judge.
Tomas Berdych held off a strong second-set challenge from Dutchman Thiemo De Bakker to win 6-1, 6-4.
It was the Czech's first appearance at the pre-Wimbledon grass event since he was defeated in the first round in 2005.
The No. 2-seeded Berdych dominated the opening set and won 70 percent of the points, but after a short rain delay at the start of the second set De Bakker held six break points before Berdych earned a vital break to lead 4-3.
Four-time champion Lleyton Hewitt also reached the third round with a 6-4, 6-3 upset victory over Grigor Dimitrov of Bulgaria.