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.
