MONTREAL — Russia's Sergey Kovalev stopped Canada's Jean Pascal early in the eighth round Saturday night to retain his three world light heavyweight titles.

The large Bell Centre crowd booed when referee Luis Pabon stopped the fight, with the dazed Pascal (29-3-1) against the ropes from a series of blows from Kovalev (27-0-1).

Kovalev looked to have won seven of the eight rounds in the scheduled 12-round bout.

Kovalev retained his WBA, WBO and IBF titles. Pascal, the former WBC champion from Montreal, was stopped for the first time in his career.