Arsenal finished Saturday's game with 10 men after Frimpong went off. He was booked in the eighth minute for inexplicably getting in Jordan Henderson's face as the Liverpool midfielder went to take a throw-in.
Frimpong's ugly tacke at Lucas Leiva on 70 minutes earned him second yellow.
On came Luis Suárez and Raul Meireles, below, who would be involved in both goals.
