The wide man finished first time, calmly volleying into the back of the net to open his account for the season.
Edinson Cavani continued to work the Bastia keeper as the clock ticked towards half time, and the visitors were lucky to get in at the break just one goal behind.
Cavani would not be denied after the restart, however. A quick free kick taken by Marco Verratti found the Uruguayan, who took the ball down on his chest and slotted into the corner to double the home side's lead.
New signing David Luiz did not have too much to do over the course of the afternoon, though he kept Bastia at bay when asked and watched calmly as his teammates made safe all three points.