Federer loses to Del Potro

  • Argentine Juan Martin del Potro ended Roger Federer's three-year unbeaten streak at the ATP World Tour Finals on Saturday to secure a semi-final against world number one Novak Djokovic.

    Del Potro claimed a 7-6 4-6 6-3 victory against the Swiss at London’s O2 Arena and assured himself of runner-up spot in Group B with a 2-1 record, the same as defending champion Federer who will face Andy Murray in the other semi-final.

    Federer beat both David Ferrer and Janko Tipsarevic earlier in the event.

    The winners will square off in the finale Monday night.

    In the doubles match, top seeds and three-times former champions Bob and Mike Bryan were beaten by India's Leander Paes and Radek Stepanek.

    Paes and Stepanek won a match tiebreak 10-7 against the Americans and will face Mahesh Bhupathi and Rohan Bopanna in the semi-finals.

    In the other semi-final, Britain's Jonathan Marray and Dane Frederik Nielson will take on Spaniards Marcel Granollers and Marc Lopez.