Top seed Andy Roddick bludgeoned his way into another semi-final on Friday as his former housemate Nicolas Thomann looked forward to the biggest payday of his unheralded career.

Wimbledon semi-finalist Roddick surged past Belgian Xavier Malisse 6-4, 6-1 in their quarter-final at the RCA championships, while Frenchman Thomann earned his place in the last four with a 7-6, 7-5 victory over German Nicolas Kiefer.

American Roddick, 20, faces Sjeng Schalken in his semi-final, with the prospect of Thomann awaiting him in Sunday's final if the 30-year-old can extend his remarkable run with success over Paradorn Srichaphan.

The second-seeded Thai eased past unseeded Australian Scott Draper 6-4, 6-2 in the later quarter-final played at the Indianapolis tennis centre.

It ensured that the top three seeds had made the semi-finals here for the first time since 1992.

Roddick and Thomann met through coach Tarik Benahabiles, with Thomann staying at Roddick's Florida home when the pair used to train with Benahabiles in Bradenton.

Thomann, a professional for seven years, has collected just $32,768 on the Tour so far this season, but the world number 169 can look forward to banking at least $25,700 just for making Saturday's semi-finals.

"I have managed to make a living," he told reporters. "But I don't know why I am in this position all of a sudden -- it is beyond my expectations.

"It feels good... of course, it has been hard at times in the last few years.

"I had a wrist injury in 1998 which kept me out for a year, and I thought about giving up the game. But I love to play so I carried on.

"I was a late developer, so perhaps there is more to come from me. It would be just perfect if I could win one match and make the final ... and then I believe I can go on playing at this level for another three or four years."

WINNING MATCHES

His previous zenith as a player came in a victory over Andre Agassi, but he said: "That was nice, but I lost the next match so really it means nothing.

"Winning matches and getting to a semi-final is much more important."

Semi-finals are becoming a habit for Roddick, the world number six who disposed of an in-form Malisse with frightening ease.

Twenty-eight clean winners had Malisse in a tailspin and not even a medical time-out at 4-1 down in the second set could steady him.

"Any time you reach the semis at your first event after switching surfaces, it's welcome," said Roddick, who will be a favourite for the U.S. Open title next month.

"But I'm focused on winning here.

"Because of the way I was serving in the first set, I felt okay, although in the last set and a half I really got some momentum going."

Dutch third seed Schalken, Roddick's opponent on Saturday, continued his progress with a 1-6 6-1 6-2 win over American Robby Ginepri, although Schalken needed eight match points to seal victory.

"He was hitting so well early on I couldn't even get my racket behind the ball," said Schalken, looking for his ninth Tour title in his ninth year as a professional.

"I did not know how to change things...fortunately I got my foot in the door and he couldn't maintain his level.

"It was a fast match, he hits the ball hard ... but with Roddick tomorrow I guess it can only get faster."