The Swede gave Laurent Blanc's men the lead, with the Argentine attacker subsequently scored soon after and at the climax to seal the win
Zlatan Ibrahimovic produced yet another masterful display to guide Laurent Blanc's men to a routine victory that took their goal tally for the season past the 100-goal mark.
The striker headed the capital club into the lead after six minutes with a goal that brought up PSG's century and marked his 38th of the campaign.
And the former Barcelona and AC Milan man played a pivotal role in his side's second goal, on 19 minutes, setting up Ezequiel Lavezzi with an acrobatic assist to all but ensure victory for the defending champions.
PSG were able to relax thereafter but still managed to add a third through Lavezzi late on as they edged ever closer to a second successive league crown.
The visitors left captain Thiago Silva on the bench ahead of Wednesday's Champions League clash with Bayer Leverkusen, while Edinson Cavani was omitted from the squad after returning to Uruguay to deal with a personal matter.
PSG almost found the net inside the first 15 seconds, Bastia defender Francois Modesto atoning for an early defensive mistake by clearing Lucas Moura's effort off the line after Lavezzi had pulled the ball back.
It did not take much longer for PSG to break through the home defence. Ibrahimovic linked up well with Lucas before the latter sent a lofted cross to the far post that the Swede directed into the net with a looping header.
Ibrahimovic was heavily involved again as Blanc's men moved into a commanding position, playing a magnificent volleyed backheel throughball into the path of Lavezzi, who slotted under Bastia goalkeeper Jean-Louis Leca to double the lead.
PSG continued to dictate play without creating too many further opportunities, although teenage midfielder Adrien Rabiot did force Leca into a save with a curling effort from range.
Blanc's men looked to have added a third shortly after the interval when Alex headed in off the bar from Lucas' corner, only for the goal to be ruled out for Thiago Motta's push on Romaric.
Substitute Yohan Cabaye then went close with a dipping volley from the edge of the area midway through the second half.
Bastia did improve marginally in the closing stages, but never looked like mounting a comeback.
A fourth straight league game without a win for the Corsicans was confirmed in the 88th minute when Lavezzi latched on to a loose ball and rounded Leca before firing home.