Defending champion Andy Roddick advanced to the semi-finals of the RCA Tennis Championships with a routine 6-2, 6-3 victory over sixth-seeded Dominik Hrbaty of Slovakia in Indianapolis on Friday.

Roddick showed no ill-effects of having to complete two matches on Thursday because of rain delays to set up a meeting with 10th-ranked Ivan Ljubicic of Croatia at the hardcourt event.

"The big difference today was in movement. I was able to run balls down," Roddick said.

The top-seeded American, who is looking for his fourth title of the season, needed just 52 minutes to dispose of Hrbaty and improve his 2004 record to 47-9.

Ljubicic overcame an on-court bee sting to rally past third-seeded Frenchman Sebastien Grosjean 5-7, 7-5, 6-2.

On the other side of the draw, unseeded Frenchman Gregory Carraz beat Israeli qualifier Noam Okun 4-6, 6-3, 6-2 to advance to his second semi-final of the season.

Carraz will play 12th seeded Nicolas Kiefer of Germany, who edged out fourth-seeded Thai Paradorn Srichaphan 7-6, 7-6 in the night match.