Del Potro fumes at umpire over 'Federer favouritism'

Juan Martin del Potro was left fuming in his semi-final loss to Roger Federer over what he thought was preferential treatment for the Swiss great.

Federer gained revenge for his US Open defeat to Del Potro on Saturday night, coming from behind to set up a mouth-watering Shanghai Masters final against Rafael Nadal.

Del Potro snared the first set against the World No.2, but started to unravel as Federer got back into the match.

The Argentine took issue with the Shanghai crowd, clearly unimpressed with the etiquette from some spectators and taking up grievances with the chair umpire.

As you can see in the video above, Del Potro engaged in a series of discussions with the umpire, including demanding Federer be warned for triumphantly hitting the ball away after winning a decisive game.

"He (Federer) scares you," Del Potro said to the umpire. "I respect you but it seems like he is different."

The momentum swung from there and Federer stormed into the final.

“Wherever Roger plays the crowd is going to be with him, and that’s something you have to deal with because Del Potro has control of the match,” British great Greg Rusedski said on Sky Sports.

“The game he got broke and he got frustrated with the umpire he knew the momentum was changing and that’s where he was starting to vent and there’s nothing the chair umpire can do.

“We want to to see crowds that get involved. We want to see animation. It cost him in the end getting that frustrated in that moment of the match."

SWEET REVENGE: Federer gets back at Del Potro for US Open upset

Nadal and Federer will meet in Sunday's final in the latest chapter in their storied rivalry.

The celebrated duo have faced one another 37 times, with the Spaniard and world No.1 Nadal winning 23 of their contests.

with agencies