Argentines Javier Pastore and Ezequiel Lavezzi scored either side of a Gaetan Bussman own goal for the visitors, who remain unbeaten this season.
But perhaps even better news was Ibrahimovic's return to the starting line-up as he managed to complete the 90 minutes, while only being denied a brace by his Argentine team-mates.
A pair of Modibo Maiga penalties had briefly brought Metz level early in the second half after turning around 2-0 down at the break, but they couldn't hold out.
Although Marseille can go back to the top by beating Bordeaux at home on Sunday, PSG's fifth straight league win and seventh in all competitions puts them top as they hunt down the early-season pace-setters.
"I was always confident even after Metz equalised. I told myself that we were going to win 3-2," said PSG coach Laurent Blanc.
"We were in charge in the first half against a Metz team who had a lot of fear and this made it easier for us."
Metz needed only a quarter of an hour to completely self-destruct, by which time they were two goals down.
First up, a succession of wayward passes and mis-controls in the centre of the park by Bouna Sarr and Ahmed Kashi allowed Pastore to steal the ball off Jeremy Choplin, ride a feeble tackle by Guido Milan and delicately dink the ball over goalkeeper Johann Carrasso.
He went to ground somewhat prematurely, just a split second before Ibrahimovic arrived to provide what would have been a finishing touch himself.
If that comedy of errors had, nonetheless, necessitated a Parisian foot to strike the killer blow, the second goal seven minutes later was entirely of Metz's doing.
Brazilian full-back Maxwell won a free-kick down the left that was swung in by Lavezzi.
But it was Metz midfielder Guirane N'Daw who then flicked it on for left-back Bussman to bundle in with his thighs as Carrasso looked on incredulously.
N'Daw came close to making amends for his part in that calamity shortly before half-time but his diving header skidded just wide.
Metz were given a lifeline early in the second half after substitute Sergei Krivets fell in the box under minimal contact from Adrien Rabiot, with the referee pointing to the spot.
Maiga sent Salvatore Sirigu the wrong way from the spot.
If that spot-kick was soft, the next one a few minutes later was cast-iron as Gregory Van Der Wiel failed to get his arm out of the way of a bouncing ball.
Maiga picked the same corner as before, and Sirigu again went the wrong way.
Metz were buoyant, in particular former West Ham United forward Maiga, and he rose highest in the box to meet a deep right-wing cross from Romain Metanire with his head, forcing Sirigu into a scrambled low save.
PSG coach Laurent Blanc threw caution to the wind with 15 minutes left, taking off midfielder Rabiot for forward Edinson Cavani, left out of the side in favour of Pastore.
And the move paid off when Lavezzi shot from distance forcing Carrasso to parry his effort straight to Ibrahimovic. The goalkeeper then got a hand to the big Swede's first time shot and although the ball appeared to be bouncing in, Lavezzi stole in to snatch the final touch from a yard out on 83 minutes.
It could have been worse for Metz with Cavani breaking the home offside trap, only for Carrasso to parry his attempted chip and then block Ibrahimovic's half-volleyed follow-up.