MIAMI GARDENS, Florida – Badou Jack wasn’t about to allow what happened to Jarrett Hurd earlier Sunday night happen to him.

Sweden’s Jack beat unknown underdog Dervin Colina by fourth-round knockout in the last undercard bout before Floyd Mayweather met Logan Paul in an eight-round exhibition at Hard Rock Stadium. Jack, who dropped Colina three times in the fourth round, won impressively in the fight following Luis Arias’ split-decision upset of Hurd in their 10-round middleweight match.

Jack (24-3-3, 14 KOs), a former super middleweight and light heavyweight champion, was listed as a 20-1 favorite versus Colina by the William Hill sports book. Colina (15-1, 13 KOs) took this huge step up in competition on barely one week’s notice.

The unproven Venezuelan veteran replaced WBA world light heavyweight champion Jean Pascal (35-6-1, 20 KOs, 1 NC), who was removed from his 12-round rematch with Jack after testing positive for four banned substances.

Jack scored a knockdown less than 20 seconds into the fourth round after landing a right hand to the body and then four power punches to Colina’s head. Approximately 30 seconds later, Jack dropped Colina again, this time with a right hand to the body.

Colina got up again, but he appeared to go down the third time from an accumulation of punches. Referee Frank Santore Jr. stopped the fight following that third knockdown, at 2:57 of the fourth round.

Colina was bleeding from his mouth and flat on his back when their scheduled 10-rounder was halted.

A hard, overhand right by Jack knocked Colina backward with 1:23 to go in the third round. Santore deducted a second point from Colina for holding about 10 seconds later

Colina continued to hold Jack in the second round. Santore eventually had seen enough and deducted a point from Colina with eight seconds to go in that second round.

Jack was aggressive as soon as their fight started, but Colina held him numerous times during those first three minutes. Colina landed a right hand with about 30 seconds to go in the opening round.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.