CARDIFF Britain's Joe Calzaghe retained his WBO world super-middleweight title on points after a bruising battle against former IBF champion Charles Brewer on Saturday.

Calzaghe, determined to export his reputation from Europe to the United States, outlasted the American to defend his title successfully for the 10th time on a unanimous decision.

The resilient Welshman is now unbeaten in 33 fights, 27 of them knockouts or stoppages, while Brewer has lost nine of his 46 fights, Reuters reported.

"That was hard," Calzaghe said. "I give him full respect. He's a true warrior."

Both fighters started at a furious pace, exchanging heavy blows from close and long range at the Cardiff International Arena. Calzaghe, however, received a stern reprimand from his father and trainer Enzo, annoyed that the champion had not kept his distance early on.

Calzaghe was soon landing the more telling punches before Brewer came back well in the third.

Calzaghe continued, however, to land more shots, quicker to the punch, before taking a step back and keeping his distance in the fifth.

Brewer had clearly surprised him with his resilience and stamina, the Philadelphian landing a fine left hook as he suddenly took the offensive at the end of the seventh round.

Calzaghe's overall superior work rate, however, meant that Brewer, gradually slowing after needing two attempts to make the weight, soon knew he needed a knockout.

The 30-year-old champion, however, had never been floored in his professional career. Saturday was no different, Calzaghe dancing clear, frustrating Brewer inside and avoiding trouble in the last two rounds.