Indo-Romanian pair of Rohan Bopanna and Florin Mergea have qualified for the semi-finals of the season ending elite Tennis Tournament ATP World Tour Finals. Bopanna and Mergea, defeated fourth seeds Jamie Murray and John Peers, 6-3, 7-6 at the O2 Arena in London in round robin stage. Earlier, the duo had unsettled top ranked and multiple Grand Slam winning team of Bob and Mike Bryan. The duo will be taking on Italian pair of Simone Bolelli and Fabio Fognini tomorrow in another round robin match. Meanwhile, in the singles event after four losses in six match-ups this year, Swiss giant Roger Federer defeated world number one Novak Djokovic 7-5, 6-2 in round-robin action and in process qualified for semi finals as well.