Arsenal have it all to do if they are to reach the Champions League final, following a narrow 1-0 defeat to Paris Saint-Germain in the first leg of their semi-final tie.
Ousmane Dembele struck early, netting the decisive goal just four minutes in, setting the tone for a thrilling contest packed with opportunities at both ends.
Arsenal responded with intent, as Leandro Trossard and Gabriel Martinelli forced Gianluigi Donnarumma into a pair of outstanding saves to keep PSG ahead.
Shortly after the interval, Mikel Merino appeared to draw the visitors level, but his effort was chalked off following a VAR review.
PSG could have added to their lead late on, but substitutes Goncalo Ramos and Bradley Barcola squandered golden chances, missed opportunities that offered Arsenal a reprieve on a night where they struggled to assert control.
The Gunners now head to Paris for the second leg next Wednesday, needing a turnaround to keep their European dreams alive.