Top-seeded Janko Tipsarevic of Serbia was first into the Thailand Open quarterfinals after beating Japanese qualifier Hiroki Moriya 6-4, 6-4 on Wednesday.
Making his debut in Thailand, Tipsarevic, who had a first-round bye, broke Moriya once in each set.
''I expected a tough battle,'' Tipsarevic said. ''I saw him play in the U.S. Open from the qualifying round. He also beat Robin Haase in the first round here, so I knew there would be no walk in the park. I should have won easily as I had break points in both sets. But I'm happy to win in straight sets.''
Tipsarevic hopes to win his second title of the year in Impact Arena to boost his hopes of qualifying for the eight-man ATP Finals. He's ranked No. 9.
Gael Monfils' fine return from injury extended to the second round after he beat South African qualifier Kevin Anderson 6-4, 2-6, 7-5.
Monfils came back last week from nearly four months out with a right knee injury and reached the semifinals in Metz in his French homeland. On Wednesday, he blew a 3-1 lead in the third set, Anderson went ahead 5-4, but Monfils won the last three games to move on.
''I didn't play big tennis, just good enough to win. That's the good thing,'' Monfils said. ''I need more time to be good and confident.''
Go Soeda of Japan beat local wild card Danai Udomchoke 6-4, 7-5 for a fourth straight time, and Ivo Karlovic of Croatia defeated Marinko Matosevic of Australia 6-3 6-4.
