Mikel Merino then headed in a rebound to make it 2-2 in the 70th minute after Arsenal captain Martin Odegaard's piledriver was pushed against the woodwork by Alisson.
Merino was sent off nine minutes later for a lunging tackle on Dominik Szoboszlai but the 10-man visitors clung on for a point and almost won it as Odegaard sent a shot just wide of the post deep in stoppage time.
Liverpool, who wrapped up their record-equalling 20th English title a fortnight ago, have 83 points from 36 games with Arsenal second on 68 and still not guaranteed a top-five finish that would ensure Champions League football next season.
Reuters