World number one Roger Federer raced into the quarter-finals of $1 million Qatar Open at Doha on Wednesday, downing Greg Rusedski 6-3, 6-4 in the second round.

Apart from his big first serve, Rusedski failed to mount any real challenge and Federer cruised through in less than an hour.

The Briton fired three aces in the first set, but Federer broke him as early as the second game and Rusedski had no answer to some blistering ground strokes and fluent backhands.

The Swiss said: "It was a good day out there for me. But I know I can play better than I did today.

"The important thing is that I didn't lose my serve. I took the opportunities that came my way and I felt quite comfortable on this surface."

Federer now plays another left-hander, Felciano Lopez of Spain, who beat Italy's Uros Vico 6-2, 7-6.

Rusedski said: "I am not disappointed. I lost to the world's number one player. Now I move on to Australia where I plan to play in a couple of tournaments before the Australian Open."

The best match of the day was an all-French affair between the experienced Fabrice Santoro and rising force Gael Monfils, who beat second seed Gaston Gaudio of Argentina on Tuesday.

Santoro, the 2000 champion here, saved a match point before edging past Monfils 6-2, 4-6, 7-5 in two hours 39 minutes.

Monfils needed medical attention after tumbling and injuring his right thigh towards the end of the match and Santoro served out for victory.