Greg Rusedski fought back to beat Jonas Bjorkman in dramatic style at the Australian Open on Tuesday.
The Briton made a sluggish start, dropping four straight games as the opening set slipped away, but a quick break in the second changed the match.
Bjorkman's game fell apart as Rusedski grew stronger and raced into the lead.
In a tight fourth set Bjorkman broke first and had two set points but Rusedski took the tie-break for a 2-6 6-4 6-0 7-6 (9-7) victory.
Rusedski will face Andy Roddick in the second round after the world number two beat Irakli Labadze of Georgia.
"I'm very pleased to get through in four sets," said Rusedski.
"It was very important to get that early break in the second set.
"That really set the momentum for the set and in the third I was all over him.
"He has got the better of me most times but I'm still undefeated in Grand Slams."
And almost a year on from clearing his name amid doping allegations, Rusedski said he is finally back to somewhere near his best.
"Having gone through what I had to go through last year and the year before that with the injuries, you're either going to get weaker and disappear and fall off the planet, which I could have done when I was 168 in the world," he said.
"But I decided I was going to fight back and got to the top 50, which I think is one of my best accomplishments as a professional tennis player.
"I think it's made me stronger. I'm going to enjoy it and give everything I can to this game.
"This is the first major I've actually been able to prepare for in two years."