Steven Gerrard was sent off 38 seconds after coming off the bench against Manchester United at Anfield on Sunday.
Gerrard intentionally stepped on Ander Herrera with his boots and was immediately sent off by the referee.
Mata fired the visitors in front early in the first half, before Gerrard came on at half-time and was almost immediately dismissed for a stamp on Ander Herrera.
United doubled their lead on the hour mark with a stunning acrobatic second from Mata before Daniel Sturridge pulled one back, and although Wayne Rooney had a penalty saved in the closing moments Louis van Gaal’s side held on to move within two points of second-placed Manchester City.
It ended a run of 13 games unbeaten for Brendan Rodgers’ men, whose last defeat also came at the hands of United when they lost 3-0 at Old Trafford in December.