Soderling, who has yet to lose a set this week, will next play Michael Llodra after the Frenchman made light work of 10th-seeded Nikolay Davydenko of Russia, winning 7-5, 6-1.
Soderling got off to a strong start on the fast Bercy center court, losing just one point on his first serve in the first 10 games.
“Against Andy, it's always just a matter of taking the chances you get,” the Swede said. “And then today I think I did really well. I served pretty well. I could have put some more first serves in but my second serve was good and overall it was a good match.” Roddick struggled to return the Soderling's big serve and failed to convert the only two break chances he had.
Soderling broke Roddick for a 6-5 lead when the American buried a backhand into the net and threw his racket in anger.
Roddick then won a 39-shot rally that gave him a break point in the next game but Soderling saved it with a crosscourt forehand winner and celebrated with a fist pump.
The two-time French Open runner-up broke again in the first game of the second set and served out the match at love with an ace.
“Maybe I should move over,” Soderling said when asked if he should buy a flat in Paris. “It's a nice city and I have the best memories of my career here, both in Roland Garros and here in indoor.” Roddick said he might have lost his focus after qualifying for the ATP World Tour Finals in London on Thursday.
Soderling will also feature in the year-ending tournament from Nov. 21-28.
“The last two weeks you're kind on pins and needles trying to qualify for this thing, and it might have been a little bit of mental letdown today, which is completely on me,” Roddick said. “That's my fault. I should be professional enough not to have that.” Llodra, the only unseeded player remaining, had never advanced beyond the second round at Bercy before. But after upsetting defending champion Novak Djokovic in the previous round, he continued to make the most of the fast surface, which has been made quicker this year and perfectly suits his serve and volley style.
Llodra and Davydenko traded breaks in the first set before the Frenchman won seven consecutive games for a 7-5, 5-0 lead.
Cheered by his son and French Davis Cup captain Guy Forget in the stands, Llodra produced 30 winners and sealed the victory with a service winner on his second match point.
“It was not easy ... against Djokovic,” he said. “But I didn't want it to end there. It will be tough against Soderling, he is a great indoor specialist and he is full of confidence.” Later Friday, top-seeded Roger Federer will be looking to improve his best result in the tournament when he takes on Jurgen Melzer for a semifinal spot.
The remaining quarterfinal pits No. 3 Andy Murray against No. 12 Gael Monfils.
