Just when the world thought that Roger Federer is up and running at an elevated pace, Juan Martin del Potro stepped in to steal the show. The last quarterfinal match of the men's singles had Federer opposing del Potro in a replay of 2009 US Open final. Just like eight years ago, Federer was the favorite with the Argentine trailing from behind. But, the eventual outcome had the 28-year-old pulling another stunning win out of his The Argentine is into another Grand Slam semifinal, the first one since 2013 Wimbledon, where Rafael Nadal awaits. The dream of having a first Fedal in New York came short once more.

For Roger Federer is also the end of a bid to regain the world No. 1 seat. It's hard to believe that he could surpass Nadal at the summit.

Roger Federer and his moments of hesitation

Entering the encounter with del Potro and knowing that Rafael Nadal is already in the semis put some extra pressure on his shoulders as he got tensed in the key moments of the match. On the other side, after surviving a five sets thriller against Dominic Thiem, del Potro walked in decided to play his best match of 2017. Fuelling his game with some huge forehand winners and an overall solid tennis, he raced to a one set lead without facing a single break throughout the inaugural act. Things changed a bit in the next set with Federer getting his teeth into the match after an early break.

The Swiss star went on to win the set, and it seemed that a change of momentum was underway. The third act saw del Potro having a better start forcing Federer to fight hard to level the score. It all went into a tie-break where the 36-year-old Swiss missed several set points. Surviving that, del Potro converted his first opportunity to put his nose in front by a 2-1 lead.

The Argentine became aware of the chance he had and didn't let it slip out of his hands as he stood firmly in front. He broke Federer once in the middle of the set and when the first match point emerged he served out the match like a stone cold executioner.

Federer's bid in New York is over

The last Grand Slam of the season stood as Roger Federer's chance to write history while becoming the world No.

1 one more time. But, del Potro was there to play his own hand. For Federer, a quarterfinal at the US Open is a poor achievement but judging by his slow start is not a surprise that he wasn't able to overcome del Potro. The only regret might be that he lost just when things seemed to get better. A guy who loves symmetry, Federer won his first two rounds in five sets and then scored two straight sets win to reach the last eight. Still, despite losing Federer will end the season with a single defeat in Majors. It would have been amazing to seal the season off with a clean sheet regarding Grand Slams.

On the other side, Juan Martin del Potro seems to have found his lost mojo as US Open proves to be his best inspirational resource. He might be the dark horse of this US Open as no one seemed to give his a chance to win the title. And look at him now as he is preparing to clash with Rafael Nadal for a place in the final.