Great Britain's Laura Robson has been knocked out of the women's Olympic singles by third seed Maria Sharapova.
The 18-year-old lost her serve in game five of the first set but managed to break back and level the opener at 4-4.
The remainder of the set stayed on serve and it was down to a tie-break to decide who would move ahead in the match, with Sharapova prevailing 7-5 as Robson's serve was broken on the 12th point.
Sharapova broke at the first opportunity in the second and looked to be cruising to victory at 4-1 before Robson bounced back to move back to 4-3.
However, the Russian broke back instantly before she served out the match 6-3.
Sharapova next faces her conqueror from Wimbledon this year, young German Sabine Lisicki, in round three of the Games.
