World number-one Roger Federer of Switzerland has returned from injury to win his opening match at the season-ending Tennis Masters Cup tournament in Houston, Texas. Federer overcame Argentina's Gaston Gaudio and the rain for a straight-sets victory.

Last year's Tennis Masters Cup ended under a cloud ... literally as rain threatened to delay the closing stages of the event.

It seems the weather has a problem with the event because the first day of singles this time has been severely interrupted because of rain. Something like 5.5 hours were lost because of the weather and only one match was completed.

World number-one Roger Federer came back after a two-hour suspension to open the defense of his title by beating the Argentine Gaston Gaudio 6-1, 7-6.

"Now I am quite relieved to have played my first match, to have won it," he said. "I am happy it is over, won or lost, you know. But to have won it, of course, makes it nicer. Now I can actually build from this and I am in a good situation, you know, looking ahead for the semifinals."

Then the match between Lleyton Hewitt and Carlos Moya was delayed by more than 3.5 hours because of the rain and only 34 minutes was eventually played. Hewitt led 5-4.

They return on day two with Marat Safin to face Guillermo Coria and Andy Roddick to play Tim Henman.