Defending champion Mardy Fish reach the second round of Delray Beach International Tennis Championships, when Belgian Christophe Rochus retired at 3-3 in the third set with a back injury.

Fish arrowed 25 aces in the middle and bounced back from a 5-7 first set loss to level the match scores at 1-1 with a 6-3 scoreline in the second set.

"He’s got an annoying game for sure – makes a lot of balls, great hands, good returns,"said Fish. "Someone with good returns is sort of a nightmare for me, so not having played a lot of matches in the past few months, you don’t know what to expect"

Second-seeded Ivo Karlovic of Croatia fired 19 aces to beat Philipp Petzschner of Germany 6-3 7-6 (3). Third-seeded German Benjamin Becker ousted 2008 Kei Nishikori of Japan 6-3 1-6 6-0.

Becker said “I just tried to stay calm after I got down in the second set, and refocused for the third set. I think I did well. I came out right after the changeover in the third set and I felt good. I was a little bit more aggressive, attacked the ball, and it helped me at the end.”

In other matches  of the day , former champion Xavier Malisse of Belgium lost to fourth-seeded Jeremy Chardy of France 6-3, 7-6 (5) and Ernests Gulbis of Latvia defeated American qualifier Ryan Harrison 6-4 7-6 (5).