CHENNAI, India (AP) -- Australian Open champion Stan Wawrinka entered the semifinals of the Chennai Open with a 6-2, 7-6 (4) victory over eighth-seeded Gilles Muller of Luxembourg on Friday.

Defending champion Wawrinka, looking for a third title here, seized the initiative with a service break in the opening game.

He was stretched in the second set by the left-handed Muller, but wrapped up the tiebreaker from 4-4.

''The weather was a bit tricky with the wind but I played aggressively,'' Wawrinka said.

The top-seeded Swiss will play fourth-seed David Goffin of Beglium for a place in the final.

Goffin got past unseeded Andreas Haider-Maurer of Austria 7-5, 6-2.

''It's going to be an interesting match (against Goffin). He's a fine player and finished the last year strongly,'' Wawrinka said.

Third-seeded Roberto Bautista Agut of Spain, the 2013 runner-up, advanced after a tough 7-6 (7), 6-4 win against Lu Yen-hsun of Taiwan.

''That was a good match, it took almost two hours,'' Bautista Agut said. ''He had a chance to win the first set but I was there all the time, and confident of winning.''

He said he was looking forward to his semifinal against Slovenian qualifier Aljaz Bedene, who ousted fifth-seeded Guillermo Garcia-Lopez of Spain 2-6, 6-3, 6-2.

''We have known each other for a long time, and I'm happy to see him in the semis,'' Bautista Agut said of Bedene.