Xavier Malisse used his serve to fend off a tough challenge.

Malisse smashed 18 aces in a 6-4, 3-6, 6-3 victory against Go Soeda in a first round match of the SAP Open on Monday night.

"It was tough," Malisse said. "His ball stayed low and he hits a good backhand. I served my way out of it a couple of times and that really helped, especially in the first set. There were a couple of mistakes that I have to adjust, but besides that I'm pretty happy."

Malisse, the eighth seed from Belgium, said he was a little rusty in his first tournament since the Australian Open, where he reached the Round of 64. His serve was working, though, with nine aces in the first set. He even recorded a handful with his second serve.

"No matter how many years you play, you have to get that match rhythm," Malisse said. "I have some time to practice a little bit. I wanted to win in the first round and that's accomplished."

Malisse is looking for his first title in six years.

Soeda, from Japan, won the Hawaii Challenger in January and played in his sixth tournament.

Canada's Jesse Levine beat American Bradley Klahn, 7-5, 6-2, in the final match.

Klahn, who graduated from Stanford and was the NCAA singles champion in 2010, lost to Levine in three sets last week in Dallas.

Levine went undefeated in his only year at Florida.