PSG came from behind on two occasions to claim victory in a thrilling Classique and move back to the top of the table, one point clear of Lyon.
Bielsa's Marseille are now five points back with seven matches to play, yet Ibrahimovic refused to write off the men from the Stade Velodrome.
"I think Marseille is still there, because there are seven games and I think this will go until the end," said the Sweden striker.
"They will make it difficult for us.
"I think we have to continue being focused and take the three points to put pressure on them to take the three points that they want to take."
Ibrahimovic was delighted to come away with three points from a dramatic encounter.
"It was a very important game. The atmosphere was magic," he added.
"It was very intense, but at the end we got the three points. It was important because Lyon won their game [against Guingamp on Saturday] and put pressure on.
"Now we're back to number one, so it was a good result."
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