Roberto Firmino came off the bench to fire in a stoppage-time winner as Liverpool downed Paris Saint-Germain 3-2 in a UEFA Champions League classic at Anfield.
Kylian Mbappe appeared to have salvaged a draw for PSG after levelling the scores in the 83rd minute, but the FIFA World Cup winner then gave away possession 25 yards out from his own goal.
And Firmino, who started on the bench due to an eye injury suffered against Tottenham on Saturday, rifled across Alphonse Areola to ensure last season's beaten finalists got off to a victorious start in Group C on Wednesday (AEST).
PSG had fought back from 2-0 down, Liverpool leading thanks to a Daniel Sturridge header and James Milner's penalty, but Jurgen Klopp's men deserved to come out on top.
Virgil van Dijk and Milner forced early saves from Alphonse Areola, with the visitors having to defend a barrage of corners, and Liverpool took the lead on the half-hour mark.
Trent Alexander-Arnold's delivery from the right was slightly too deep but Andrew Robertson arrived to deliver a brilliant first-time cross that Sturridge firmly headed past Areola.
The Liverpool lead was soon doubled, Milner beating Areola from 12 yards after Juan Bernat clumsily tripped Georginio Wijnaldum in the penalty area, but Thomas Meunier gave PSG an immediate lifeline with a low volley.
Liverpool thought they had restored their two-goal cushion after the break when Mohamed Salah tapped in from close range, but it was rightly ruled out for Sturridge's challenge on Areola.
Mbappe, who had barely had a sniff of goal, seized on a loose ball after Neymar's driving run to slam home past Alisson and seemingly earn PSG a point with only seven minutes to go.
However, the France international crucially had an impact at the opposite end of the field in added time, giving up possession to allow van Dijk to feed Firmino, who arrowed in a shot to settle a pulsating contest.