Carl Pettersson of Sweden fired rounds of 60 and 67 over the weekend to go from also-ran to champion at the RBC Canadian Open. He finished one shot ahead of a faltering Dean Wilson.

The American held a four shot lead at end of day three, but he stumbled to a closing 72 while, after a slow start to round four, Pettersson resumed the charge he’d begun on Saturday.

After making the cut by only one stroke, the Swede was lucky to be competing at all over the weekend. But, a superb third round of 60 took him right back into contention.

Over the first few holes of the final round it looked as though Pettersson had used up all his birdies the previous day, as he was two-over for the round after seven holes. But a string of six birdies in the next eight holes saw him overhaul Wilson and take a two shot lead. The 32-year-old had the luxury of being able to make a bogey at the final hole and still take the title – the fourth of his PGA Tour career.

“I still can’t believe I won the tournament,” Pettersson said. “I know it’s difficult to shoot another low one after a round like that, so I was just trying to downplay it.”

Wilson had mixed feelings in losing after leading through 54-holes. Although obviously disappointed not to get the win, he was playing on a sponsor’s exemption so a second place finish was a significant result for the 40-year-old.

“If you would have told me before the week that I could be second alone, I would have been tickled,” he said.

It was another good week for England’s Luke Donald. He finished alone in third, two shots behind Pettersson. Donald has climbed to seventh on the Official World Golf Ranking.