See also: Groves v Sierra as it happened
George Groves crushed Francisco Sierra in the sixth round of an explosive clash in San Jose after being caused problems by the heavy-handed Mexican.
Groves was caught by several shots in the opening couple of rounds and a clash of heads in the third left him with a nasty cut by the side of his right eye.
There was another scare for the Hammersmith super-middleweight in the fifth when he was hurt by a crunching body shot.
But by that stage he was beginning to land with telling shots of his own – and in the following round he ended the fight in blistering fashion to maintain his unbeaten professional record.
A thunderous right-left-left combination sent Sierra to the canvas and after he unsteadily got to his feet, he was nailed by a big right and was close to being floored again when the referee stepped in to end the contest.
Injuries meant this was Groves’ first outing since his second-round demolition of Paul Smith in November.
And the cut he sustained means the proposed defence of his British and Commonwealth titles at Wembley Arena in seven weeks’ time must now be in serious doubt.