Coman also scored the only goal when Bayern overcame his former club PSG to win the trophy three years ago.

Substitute Kylian Mbappe, back after injury, looked to have rescued a draw for the hosts, but his late effort was ruled out for offside in the build-up.

Ligue 1 champions PSG have now lost their last three matches in all competitions.

In contrast, Bayern are unbeaten in all competitions since 17 September and now favourites to reach the quarter-finals, despite having defender Benjamin Pavard sent off for a second booking in injury time.

PSG were boosted beforehand with Lionel Messi fit enough to start up front after recovering from a hamstring injury, while Mbappe was on the bench.

There was also a start in midfield for Warren Zaire-Emery who, at 16 years and 343 days, became the youngest player ever to start a Champions League knockout stage game.

The Frenchman was born in 2006, the same year in which Messi, 35, won his first Champions League title.

Mbappe, initially expected to miss this match with a thigh injury, was brought on after 57 minutes, but was clearly far from full fitness.

PSG struggled to create any chances of note in the first half, while Bayern dominated possession but lacked a cutting edge until Coman struck in the 53rd minute.

The winger, who started in the youth team at PSG, met a deep Alphonso Davies cross from the left with a first-time volley.

Coman's effort squeezed under PSG keeper Gianluigi Donnarumma, although the Italian made up for it later with superb saves to deny Eric-Maxim Choupo-Moting and Pavard.

Mbappe's arrival lifted PSG and Yann Sommer kept out his close-range shot before the Bayern keeper was beaten in the 82nd minute.

Home celebrations were cut short, though, as left-back Nuno Mendes was ruled narrowly offside by the video assistant referee (VAR) before he delivered a cross for Mbappe to finish into the roof of the net.

Following losses to Marseille in the Coupe de France and Monaco in Ligue 1, another damaging defeat piles the pressure on manager Christophe Galtier.

PSG, who have still never won the Champions League, now face a tough task in the return leg in Germany on 8 March.