LONDON — David Haye made an easy jump from cruiserweight to heavyweight today, flooring Monte Barrett five times in five rounds.

Watched from ringside by WBC champion Vitaly Klitschko, former undisputed world cruiserweight champion Haye showed his full range of shots at O2 Arena, although the Ukrainian saw he could also be an easy target.

Haye had Barrett down twice in the third round, once in the fourth and produced a right-left combination that had Barrett down again in the fifth of the non-title bout.

Barrett, who has lost to Nikolai Valuev and Hasim Rahman in world title fights and also was knocked down five times by Klitschko's younger brother Wladimir, showed no sign of getting up this time and referee Richie Davies, having started the count, called an end to the contest.

It was Haye's 22nd victory against one loss, and Barrett's seventh defeat against 34 victories.

Barrett's arrival in the ring was a disaster. The American decided to leap over the top rope, caught it with his leg and wound up hitting the canvas before his opponent got into the ring.

Barrett sent Haye sprawling to the canvas in the middle of the second round but it was clearly a push. But he cornered the British fighter with an overhand right followed by a short left flush to the chin.

Haye came up with a big left hook that put Barrett down with half a minute to go of round three, and caught him with a right uppercut that brought a second count.

Haye landed a left and right for a third knockdown and was renewing the attack when the bell sounded to end the fourth.

Barrett had Haye down again in the fifth but the referee ruled it a slip and warned the American, who had clipped the British fighter's head with a punch while he was down.