TORONTO (AP) -- Roger Federer beat pesky Argentine challenger Juan Ignacio Chela 7-6 (7), 6-3 in his opening match at the Rogers Cup on Tuesday night.
The third-ranked Swiss star allowed Chela back into the first set, before prevailing in the tiebreaker. He was not as generous in the second set, which lasted 34 minutes.
Federer, seeking his third Rogers Cup title, was playing his first match since losing in the quarterfinals at Wimbledon. He had largely withdrawn from the sport after his early exit, going on vacation and, aside from a handful of sponsor appearances, disconnecting from the public.
"There's many things I'd like to do, but I'm not going to say my career is incomplete if I don't get to it,'' Federer said. "I'd love to win another 10 Wimbledons, another five French Opens, an Olympic gold in London, a Davis Cup and whatever - you name it.''
Federer won the Canadian tournament in 2004, and then again two years later. He improved to 23-6 in his career in Canada.
"I thought it was a good match, overall,'' he said. "It's always nice to come back after six weeks and get the win. I think that's what counts the most tonight. It's normal that you're a bit rusty after six weeks.''
Top-seeded Rafael Nadal plays his first match in the singles draw Wednesday and could meet Federer if both advance to the final.
The tournament lost one big name on Tuesday when American Andy Roddick withdrew with an undisclosed illness. The eighth seed will be replaced by France's Paul-Henri Mathieu.
After losing in straight sets in the third round at Washington last week, Roddick said he "didn't feel right physically.''
Roddick dropped to No. 11 in this week's ATP rankings, the first time since the rankings began in 1973 that there is no one from the U.S. in the top 10.
In second-round action Tuesday, Wimbledon runner-up Tomas Berdych ousted Sergiy Stakhovsky 6-2, 6-4 in 90 minutes.
"I know him quite well, what his style of the game is, and it's always tough,'' Berdych said. "He's playing a lot of slice, chip-and-charge and coming to the net, and sometimes really fast, coming in from the baseline. You don't know what to expect.''
It was a win for the 24-year-old in a season perhaps better known for its losses. Berdych lost in the semifinal round at the French Open, and followed that with a loss to Nadal in the Wimbledon final a month later. And, after winning his first match on Tuesday, he said he would not trade either experience.
"These are the best moments,'' he said. "If you have money, you can buy whatever you want, but these - the memories from the tennis - are really nice. This is the reason why you are doing this sport.''
Berdych, ranked No. 7 on the ATP World Tour, has won five singles titles over his career, but none this year.
"I wouldn't change it for anything,'' he said. "I was really sad that it didn't happen in Wimbledon, because there was really something special, that I'd never been in a Grand Slam final.''
Fifth seed Robin Soderling survived a scare to emerge with a 4-6, 6-4, 6-4 win over Ernests Gulbis, while Argentine David Nalbandian scraped to a 7-5, 3-6, 6-3 victory over 10th-seeded Spaniard David Ferrer.
Frank Dancevic will also play in the night cap on center court, facing off against Switzerland's Stanislas Wawrinka.
In other matches, Serbia's Viktor Troicki upset 11th seed Marin Cilic 6-4, 7-6, while Ukraine's Alexandr Dolgopolov earned a 1-6, 6-2, 7-6 win over Germany's Philipp Petzschner. Italy's Fabio Fognini won 6-2, 6-4 over the Czech Republic's Radek Stepanek in another early match.
Also, Chile's Fernando Gonzalez has withdrawn with a left calf injury and will be replaced by India's Somdev Devvarman.