World number one Roger Federer shrugged off sweltering conditions to ease into the third round of the Nasdaq-100 Open on Saturday with a 6-3, 6-1 win over Olivier Rochus.

Federer needed just 71 minutes to put the Belgian away and extend his winning streak to 17 matches.

The Swiss has now won 43 of his last 44 matches, stretching back to the beginning of last August's U.S. Open, and has been beaten only once this season. That defeat came against Marat Safin in the semi-finals of the Australian Open in January.

Since then Federer has won consecutive titles in Rotterdam, Dubai and, last week, in Indian Wells.

Britain's Tim Henman is also through to round three after an efficient 6-3, 7-5 win over Czech lucky loser Ivo Minar.

"It's really hot out there. Those are conditions where you don't want to be out there any longer than necessary," said Henman.

Last year's runner-up Guillermo Coria safely negotiated his opening match against Davide Sanguinetti, beating the Italian 6-1, 6-4.

Argentina's Coria had to retire from last year's final against Andy Roddick with back pains caused by kidney stones. Roddick retired from the tournament on Friday with a wrist injury.

Women's top seed Amelie Mauresmo was given a scare by young Russian Maria Kirilenko before winning 4-6, 6-4, 6-1.

Mauresmo said she might have benefitted from the 10-minute break players are given before the third set under the WTA Tour's extreme heat rule.

"I was capable of coming back on court after the break and really being able to give 100 percent. Maybe it wasn't really the case for her," she said.

"She played really well (in) that first set especially. It took me a little time today and I finally got my game together."