Las Vegas, NV -- (Sports Network) - Welshman Joe Calzaghe kept his perfect record in a split-decision win over Bernard Hopkins on Saturday night in the Thomas & Mack Center.

Calzaghe (45-0) rebounded from a first-round knockdown at the hands of "The Executioner" to seemingly win easy, however one judge did give the 43-year-old Hopkins the fight by a score of 114-113. The other two judges scored in favor of the 36-year-old from Newbridge, though, 116-111 and 115-112.

Hopkins (48-5-1) floored the favored Calzaghe in the first round, but was dominated for much of the fight, and suffered his first loss since dropping consecutive decisions to Jermain Taylor in July and December 2005.

Known as one of the greatest middleweight champions of all-time, Hopkins stepped up to light-heavyweight to dethrone Antonio Tarver in June 2006 and then beat Ronald "Winky" Wright on July 21 of last year. He ran into an unstoppable force in the form of Calzaghe, however, who was making his first fight in the U.S.

Calzaghe looked in trouble early, as a right to the chin from Hopkins sent him to the mat. The Welsh southpaw quickly made up for the knockdown, though, and took control in the third round, landing a series of hard left hands late in the round to Hopkins' head. The fighters traded combos to the bodies before the bell sounded.

Calzaghe landed a series of hard jabs at the end of round eight, and began showboating as the bell sounded, making faces at Hopkins before hopping back to his corner.

The fight stopped for a bit early in the 10th round after Hopkins claimed he took a low blow. Replays showed a borderline punch by Calzaghe to the waistline, which sent Hopkins reeling. The showman Calzaghe shook his hips at "The Executioner" as Hopkins was doubled over, and Hopkins ultimately fell to the mat. No point was deducted from Calzaghe for a low blow, but the referee allowed Hopkins to take a minute or so to recover before the fight resumed with 2:21 left in the round.

Hopkins claimed another low blow with 28 seconds left in the 11th, but was given no time to recover this time. He threw two hard rights after the brief stoppage, but Calzaghe came right back and landed two of his own before the bell sounded.

Both fighters were aggressive in the 12th round, but Hopkins couldn't land enough shots to make up the difference.