Japan's 15th seed Kei Nishikori has secured his place in round two of the men's Olympic singles thanks to a straight-sets win over Australian Bernard Tomic.
With both players dropping a service game in the opening set, it was Nishikori who finally came through with a 7-4 triumph in the tie-break.
It was an even tighter affair in the second as both men held serve to force another tie-break. It was Nishikori who again came out on top 7-4 as he saw off the Aussie youngster.
The world number 19 will now face either Czech Radek Stepanek or Russian Nikolay Davydenko in the second round.
