With all eyes on defending champion Maria Sharapova and world number one Serena Williams, Italian Schiavone, the 2010 Roland Garros winner, had gone unnoticed until she ended Bartoli's run in ruthless fashion on Court Suzanne Lenglen.
Bartoli fought until the end but there was little she could do against Schiavone's sliced backhands, spinning forehands and cunning lobs that got the better of the Frenchwoman after 78 minutes.
Next up for the unseeded Schiavone, who is also the 2011 French Open runner-up, is third seed Victoria Azarenka of Belarus.
Bartoli admitted she was impressed by Schiavone's claycourt skill - although, having been beaten by the Italian in the semi-finals here in 2011, it came as little surprise.
"On clay she's always very dangerous and she won a clay court tournament again this year and this is a surface that suits her," the Frenchwoman said.
"When she starts winning matches and becomes more confident, then she can be very dangerous. So maybe she can sort out Azarenka and then if she arrives in the quarter-finals, who knows what can happen?"
Bartoli had started confidently, breaking Schiavone's serve in the first game but Schiavone just had too much in her claycourt repertoire as she raced to a 4-1 lead.
She won seven games in a row to move 6-2 5-0 up and although Bartoli kept fist-pumping on every point, she had to admit Schiavone was a class above her on the slow surface.
"On clay she is a terrific opponent," said Bartoli. "It's the second time of course she's beaten me here and I think that it's twice to many. On clay this is a player who is very, very dangerous."