The sixth-seeded Roddick was upset by 44th-ranked Marin Cilic 6-4, 4-6, 6-4 Thursday.

“His aggressiveness is what won him that match,” Roddick said. “He took it to me a lot more than I took it to him.”

Defending champion Novak Djokovic advanced to the quarterfinals with a 6-4, 6-4 win over Robin Soderling.

“I played more or less at the level which was satisfying for me,” Djokovic said.

With two top players already eliminated, the road to the final has been blown wide open.

“I just pay attention to my matches,” Djokovic said. “Having the role of a favorite in most matches I play, obviously I'm put in a lot of pressure. I have a lot of responsibilities and expectations, so it's not easy.”

Roddick claimed he wasn't looking past Cilic at a draw that no longer featured Federer in the way.

“I don't know if I'm playing well enough right now to look ahead in the draw,” he said.

Gilles Simon, who upset the top-ranked Federer on Wednesday, advanced with a 6-3, 6-4 win over Jose Acasuso.

Also, eighth-seeded Andy Murray of Britain advanced with a 6-2, 0-6, 6-4 win over ninth seed Stanislas Wawrinka of Switzerland.

Rafael Nadal, Nikolay Davydenko and David Ferrer were scheduled to play later Thursday.

Cilic broke an indifferent-looking Roddick in the third and seventh games before taking the first set, despite a shaky 50 percent first-serve percentage.

Roddick rebounded in the second set, perhaps drawing inspiration from a crowd that was firmly in his corner. Amid occasional chants of “Go Andy Go” and “Let's Go Andy,” the 25-year-old American played patiently, waiting for Cilic to make mistakes.

“(The) crowd helped him a little bit to get his mental side back,” Cilic said.

Roddick broke him in the eighth game and again in the 10th, when Cilic's double fault evened the match and earned a fist-pumping Roddick a rousing ovation.

But the 19-year-old Cilic wasn't fazed. He broke Roddick in the first game of the next set, and Roddick couldn't get it back.

“I was moving him around quite good and exposing him on both sides,” said Cilic, ranked 44th in the world. “That was working very well. He obviously didn't have a lot of chances to attack, which was a really good thing for me.”

Cilic, who will play Simon in the quarterfinals, said the win stands among the best of his career.

“You don't have a chance to beat top 10 players every month, so it's a good effort,” he said.