Elena Baltacha has become the first British casualty of this year's French Open by losing in straight sets to Australia's Samantha Stosur.
Sixth-seed Stosur raced into a 3-0 lead before Baltacha got on the scoreboard in game four.
Baltacha, the world number 68, fought back to within a game of Stosur but lost out in the tenth game as Stosur took the opener 6-4.
US Open champion Stosur again broke clear in the second and this time maintained her momentum in reaching 5-0 in double-quick time.
Baltacha went 0-40 down on serve and showed a glimpse of quality by first sending a drop shot just over before belting an unstoppable backhand to save two match points.
She could do little on the third as Stosur ran round her backhand and smashed a forehand up the line to seal victory.
Stosur will next face either American Irina Falconi or Romania's Edina Gallovits-Hall in the second round.