Jorge Lorenzo admitted that he thought he was beaten in the Qatar Grand Prix as Casey Stoner pulled away from him in the middle of the race.
Yamaha rider Lorenzo trailed Stoner's Honda until the closing laps, when he hunted down and passed the reigning champion as Stoner began to struggle with an arm issue.
Lorenzo said he had always hoped there might be a chance to snatch victory if he could keep Stoner - who had hit the front on lap three - in sight, but had little expectation of winning.
"It was a race similar to Jerez 2010 for me," said Lorenzo. "In the middle of the race, I thought it was impossible to win this race.
"But this victory is because I never gave up, was always pushing, always trying - and also because Casey lost the pace a little bit. So I kept pushing."
Lorenzo had taken pole position on Saturday, when second-place qualifier Stoner feared a chattering issue would compromise his race. But Lorenzo reckoned Honda took a big step forward on Sunday.
"I think the Hondas found a little bit in the warm-up so it was very difficult to beat them in the race, but I put everything I had, all my energy, onto the track and in the end I won this race," he said. "It's wonderful."