Luis Diaz starred with two first-half goals before being sent off for a reckless tackle on Achraf Hakimi, who left the field in tears with an ankle injury. Ousmane Dembele had already departed injured after his early effort was ruled out for offside.
Bayern's intense pressing unsettled PSG, and Diaz struck twice - first from close range inside five minutes, then capitalising on Marquinhos' error to double the lead. His red card just before half-time gave PSG hope, and substitute Joao Neves pulled one back with a 74th-minute bicycle kick.
Despite heavy late pressure, including fine saves from Manuel Neuer, Bayern held firm to claim all three points and stay top of their group with 12 points from four games.
Coach Vincent Kompany praised his side's composure but cautioned: "The Champions League isn't decided now - these are just important steps."
The first major flashpoint arrived when Dembele's apparent equaliser midway through the opening half was ruled out for offside following a brief VAR check, moments before the winger limped off with a calf issue. Bayern then almost went 3–0 up when Serge Gnabry's strike hit both posts in quick succession, leaving PSG's defence visibly rattled.
Soon after, Diaz's rash challenge on Hakimi drew fury from the home crowd. Initially shown a yellow, the Colombian was dismissed after the VAR review confirmed contact above the ankle. Hakimi, in tears, was carried off and later seen leaving the stadium on crutches.
The second half was littered with frantic moments as PSG pressed for a leveller. Neuer produced two outstanding saves - first tipping Neves' deflected shot over, then denying Zaire-Emery from point-blank range in stoppage time. Bayern, reduced to ten men, clung on amid heavy pressure to secure another statement win in Europe.
Paris Saint-Germain will attempt to move back to the Ligue 1 summit tonight when they host a resurgent Stade Rennais, with Luis Enrique urging his players to show a stronger response after last weekend's setback against Monaco.
VfB Stuttgart will aim to maintain their strong home record when they host Bundesliga leaders Bayern Munich this weekend.
Bayern Munich's push to secure Dayot Upamecano's future has accelerated, with the German champions deep in negotiations over a new long-term contract as the defender moves into the final seven months of his current deal.
Paris Saint-Germain are facing a worrying goalkeeping dilemma after Lucas Chevalier emerged as a major doubt for their Ligue 1 meeting with Rennes on Saturday.
