Rusedski was forced to qualify because his ranking plummeted while he was fighting his innocence, and after beating the 2000 champion Thomas Enqvist 3-6, 6-3, 6-2 in the first round claimed he had something to prove.

"The nice thing is coming into press conferences and talking about winning matches. You could pick anyone in the locker room with the same situation as me," Rusedski said on Monday, referring to the risk of contamination causing a positive drugs test.

Rusedski also said: "I think I have something to prove. A lot of people had written me off and I think I have answered them pretty well in the last three or four weeks.

"Some people said I would be on the Challenger circuit every week or even playing Futures tournaments," Rusedski said, later adding: "Every time I have had a problem in my career I have come back."

Rusedski is doing just that despite a lack of the wild cards which he had hoped the ATP's recommendation to tournaments would secure for him, following a successful appeal against a positive test at a Montreal tribunal earlier this year.

Since then the former world number four has won the Campbell Hall of Fame title in Newport, Rhode Island, risen from outside the top 100 to 88 in the world, and ensured himself a place at the U.S. Open where he was a finalist in 1997.

"I proved a lot to myself by winning Newport after everything I have been through," he said.

"And this week I have proved that I deserve a main draw place."

Rusedski's next opponent is Argentina's Gaston Gaudio, the French Open champion and ninth seed, who may struggle to live up to his ranking on hard courts.

Earlier, two other former champions, Carlos Moya, the 2003 winner, and Andre Agassi, a winner in 1995 and 1996, narrowly survived first round scares.

Moya was a set down and a break of serve down at 2-3 in the second set against another British qualifier, Arvind Parmar, before winning 3-6, 7-5, 6-3.

Agassi was within a handful of points of defeat in the second set tie-breaker against Mardy Fish, before winning 4-6, 7-6, 4-1 when his fellow American pulled out with a bad back.

It was a measure of revenge for Agassi's emotional loss to Fish in San Jose in February.

"I am just trying to get my game back to where I know it can be," the 34-year-old Agassi said, making an oblique answer to retirement speculation.

"I hope I can see my best tennis again. But you know only time will tell."