After a damaged pitch at the Parc des Princes saw the fixture reversed and held at Rennes' Roazhon Park instead, it was Franck Haise’s men who made a blistering start in Brittany.
Adrien Thomasson found Sebastian Szymański free on the edge of the box, and the Polish midfielder unleashed a spectacular strike beyond the reach of Matvey Safonov to give the hosts an early lead inside nine minutes.
Undeterred by that surprise setback, the five-time consecutive French champions thought they’d drawn level in the 21st minute, only for Désiré Doué’s smart finish to be ruled out for offside.
PSG continued to push for an equaliser as the first half progressed, with Ousmane Dembele powering a close-range effort narrowly over the bar.
The visitors were undone once again in the 38th minute, however, when Esteban Lepaul swept a brilliant first-time finish into the bottom corner from Przemysław Frankowski’s cut-back.
Desperate to gain a foothold in the contest, Luis Enrique’s men upped the ante before half-time, but Brice Samba remained alert in the hosts’ goal, thwarting João Neves from 12 yards.
New signings Torres and Mika Godts were introduced at the break, and the visitors nearly pulled a goal back at the start of the second period, as Doue and Warren Zaïre-Emery were denied in quick succession by Samba.
Having won nine of their last 11 season-opening Ligue 1 matches (D1, L1), PSG piled on the pressure with time heading into the final 25 minutes, and their persistence was duly rewarded in the 71st minute, with debutant Torres finishing coolly from Fabián Ruiz’s long ball.
Armed with the momentum, Enrique’s side went close to drawing level just five minutes later, as a powerful strike from Doué flew inches over the bar.
The Parisians didn’t have to wait long for an equaliser, though, with Torres heading home from Fabián’s inviting delivery to set up a grandstand finale.
PSG went in pursuit of snatching a late winning goal, but the hosts regrouped to earn a deserved point, as they missed the chance to secure a fifth successive opening day victory in Ligue 1.
Flashscore Man of the Match: Ferran Torres (PSG)