Eight years after losing to Juan Martin del Potro in the US Open final, Roger Federer locks horns again with the giant Argentine in New York still convinced he should have won the match which ended his five-year reign as champion.

Del Potro was just 20 years old when he downed the Swiss legend 3-6, 7-6(3), 4-6, 7-6(4), 6-2 but Federer believes that he was the dominant force in that 2009 showdown.

“The only time when he was really better, in my opinion, was the fifth set. Obviously that was good enough to beat me that day,” said Federer on Monday after seeing off Philipp Kohlschreiber 6-4, 6-2, 7-5 to set-up Wednesday’s quarter-final with del Potro.

“I felt like that I left that match with a lot of regrets. Probably feels like one of those matches I would like to play over again.

“Feel like I would probably win it somehow because I should have been up maybe two-sets-to-love.”

Bitter memories of 2009 final

Federer leads Del Potro 16-5 in their head-to-head record although his win in Miami this year represented the first time the pair had met in four years.

Despite his disappointment at losing the 2009 championship match, Federer admits that having also defeated Rafael Nadal in the semi-finals, del Potro was overall a worthy winner.

Federer had already won the French Open, to complete the career Grand Slam in 2009, before going onto to win a sixth Wimbledon.

He also became a father for the first time. “Making the finals here was actually a good run. But it ended my five-year reign in New York,” he said.

Federer believes that had Del Potro remained fit he could have become world number one after that breakthrough. For del Potro, beating Federer should have meant he had the world at his feet.

Sadly, it was his wrists which proved the problem as he went on to undergo four surgeries. After his 2009 triumph, he was to miss a total of 10 Grand Slam tournaments.

At one stage last year, his world ranking, once as high as four in the world, slumped to 1,045 and he even considered retiring. Federer said he was happy to see the likeable Del Potro back on tour and the feeling is mutual. “I admire him, too. Everybody loves him,” said Del Potro. “It’s going to be an interesting match to play. It will be the fitst time after eight years again in the central court of this tournament.

When asked rushing a player during the game featured prominently in his plans, the 36-year-old said that with him, it was a case of mixing it up. He said: “I think I’ve always been trying to do that a little bit throughout my career. Maybe it’s not rushed, per se, against every player. Mixing it up, not making the opponent feel comfortable. I think that’s always been a goal for me.

That treatment, I get the same from a lot of players. They always play what you don’t want to see. That’s why actually you improve a lot in the beginning stages of your career. If you have a weakness, they’ll go there day and night. They make you improve it fast because they remind you how bad you are on your backhand side or your footwork, whatever it may be.”