The last time the pair met Williams cantered to victory in a 6-0 6-1 win at last month’s US Open but her Italian opponent made it more of a contest this time out.
The first set was relatively comfortable for the world number one as she converted one of her three break-point opportunities, but the second was a closer affair as the US Open winner had to draw on her ample experience to see out the match.
Schiavone broke early and led 3-1 at one point but the 17-time Grand Slam winner managed to level things up at 3-3.
However, 2010 French Open champion Schiavone managed to re-group and fashioned three set points having taken a 5-3 lead but Williams won four games on the bounce to secure the match.
Sister Venus Williams did not fare as well, going down 6-1 6-2 to Sabine Lisicki.
Williams committed 22 unforced errors and three double-faults as Wimbledon finalist Lisicki rattled off 29 winners to win in just 53 minutes.