London: World No.1 Roger Federer was forced to dig deep to avoid a first-round Olympic tennis tournament exit Saturday after stiff resistance from Colombia`s Alejandro Falla.
Swiss player Federer took the first set with ease but world No. 51 Falla fought back in the second and held serve to 3-3 in the decider before Federer moved up a gear to seal a 6-3, 5-7,6-3 win.
In the second round Federer will face French world No. 32 Julien Benneteau, who beat Russian No.1 Mikhail Youzhny 7-5, 6-3.
Elsewhere, Spanish world No. 12 Nicolas Almagro qualified with a 6-4, 7-6 win over Serbia`s Viktor Troicki.
Serbian No. 2 Janko Tipsarevic eliminated Argentinian player David Nalbandian 6-3, 6-4, while Steve Darcis of Belgium upset former Wimbledon finalist Tomas Berdych 6-4, 6-4.