Andy Roddick started slowly but picked up his game steadily to beat Philipp Petzschner of Germany 4-6, 6-4, 6-1 at the Delray Beach International Tennis Championships on Tuesday night.

The fourth-seeded Roddick's game is clearly rusty. He's been dealing with a right hamstring and right ankle injury this season and came into the match with a 2-3 record and a No. 30 ranking, his worst in over a decade.

"For me it was just a matter of trying to find it at some point," said Roddick, who played his first ATP Tour match at this tournament in 2000. "I was returning really badly early on. I'm just glad I finished strong. From 4-all in the second set I played really well."

Earlier, Top-seeded John Isner outlasted fellow American Jesse Levine 6-4, 7-5 (15) in their first-round match.

The 61st-ranked Petzschner was in charge of his first career match against Roddick for the first set and a half. Even after Roddick broke his serve in the fourth game of the second set — the German double-faulted at 15-40 to surrender his serve — Petzschner recouped the service break in the next game.

The match turned in Roddick's favor when Petzschner mis-hit a ball into the air at 30-40 in the 10th game for the American to even the score at one set apiece.

By the third set, Roddick's forehand was dictating points and his serve was becoming more potent.

Roddick raced to a 3-0 lead and broke serve again in the sixth game. He closed out the match with a love service game.

"It started coming around tonight," ''I felt okay in practice the last couple of days. The biggest thing is getting to transfer over to a match in match conditions.

"It takes one (match) to get going and, hopefully, this is the one."

Isner barely held off a tenacious Levine, who is ranked No. 133 in the world and needed a wild-card entry into the main draw.

Levine, who lives nearby in Boca Raton, trailed the 11th-ranked Isner throughout the tiebreaker. The match ended when Levine's backhand hit the top of the net and carried long, putting Isner into the second round.

Isner, playing against his fourth straight left-hander, won on his sixth match point — all on Levine's serve. Levine had five set points in the second set.

"I served very well and to be honest I was very lucky to win it," said Isner, who had 13 aces. "To be honest, if I lost that second set I didn't really fancy my chances in the third because the humidity was getting to me.

"I was very lucky to advance."

Isner is 9-1 in tiebreakers this year, with the lone loss coming in the quarterfinals to eventual champion Jurgen Melzer in Memphis last week.

The second set marked the longest tiebreaker Isner has ever played. He won a second-set tiebreaker 16-14 over Victor Hanescu in the first round of the 2009 U.S. Open.

Levine has been working on improving his ranking on the Challenger circuit. His last ATP World Tour win was against American Ryan Harrison in the first round of the June 2010 Queen's Club tournament.

In another first-round match, Jarkko Nieminen of Finland, ranked 43rd, beat second seed Marin Cilic of Croatia 6-3, 3-6, 6-2.

Nieminen has already won a title this year at Sydney, while Cilic was playing his first match of the season. The 21st-ranked Cilic has been nursing a left knee injury and this was his first match since last November.

Known for a big serve, Cilic racked up nine aces — but he was streaky. His first-serve percentage was only 48 percent.

"It was my first match for a while and it felt a little bit awkward I would say," Cilic said. "I played some moments pretty good but I think my fitness level, not great. ... I expected that to happen."

Also during the day session, fifth seed Philipp Kohlschreiber of Germany defeated Olivier Rochus 6-1, 6-4. Latvian Ernests Gulbis, the 2010 Delray Beach champion, beat Alejandro Falla of Colombia, 6-4, 6-1. And Belgian Xavier Malisse, a two-time Delray Beach champion, scored a 7-6 (3), 6-3 win over Guillermo Garcia-Lopez of Spain.