Roger Federer says he has 'extra incentive' to win this year's US Open after falling agonisingly short of a sixth-straight title in 2009.
Federer, 29, went down in five sets to Argentinean Juan Martin Del Potro in last year's final, ending a winning streak of 40 straight matches over five years at Flushing Meadows.
But the Swiss maestro says the memory of that loss will serve him well when he faces another Argentinean, world No.92 Brian Dabul, in the first round on Monday (US time).
"If there is a final that I shouldn't have lost, it was that one," Federer told Tribune de Geneve.
"I had a hard time swallowing it. Maybe there's an extra incentive after being just two points away last year."
Unlike previous years, however, Federer won't be coming into the year's final Grand Slam as a strong favourite, particularly given that the world No.2 has looked unconvincing since winning the Australian Open in January.
In June, the 16-time Grand Slam champion was bundled out of the French Open by Robin Soderling, losing his world No.1 ranking to Rafael Nadal in the process.
Less than a month later, Federer suffered a shock loss in the Wimbledon quarter-finals as Czech Tomas Berdych left him two matches short of an eighth successive final at the championships.
"I look back at the last six years and I've been incredibly successful," Federer said.
"Over time, I learned to accept losses, although none makes me happy, especially if it occurs in the quarter-finals at Roland Garros and Wimbledon."
"But it's always my ambition to win Grand Slam titles. I know I have a chance in New York, it really excites me."
Federer took some time off following his loss at Wimbledon and returned to the ATP circuit on the hardcourts in the US and Canada.
He was defeated in the final of the Toronto Masters by Andy Murray, but claimed his first title in eight months when he retained the Cincinnati Masters trophy in August.
Now, Federer says he is looking forward to getting underway at Flushing Meadows, and would love to meet his main rival Nadal in the final.
"I think it would be great to play Rafa here," he said.
"We have played in all the other majors but this one is missing. I hope we can do it this year, but if not we will both be around a little longer."
"I would love to play him but it can only be the final so we have some work to do first."