Chris Billam-Smith lost by unanimous decision in his cruiserweight world title unification fight with Gilberto 'Zurdo' Ramirez in Riyadh.
The Mexican added the WBO title to his WBA belt after winning 116-112, 116-112 and 116-113 on the judges' scorecards.
Ramirez took control from the early stages and caused a cut to the Briton's eye which worsened as the fight went on.
Billam-Smith had made a solid start in the opening round, landing some quick punches, but Ramirez responded in the second with some good combinations and landed a tight left hook.
Both fighters landed blows in the third and Ramirez caught Billam-Smith on the lip, but the Briton replied with a solid hook and uppercut.
Ramirez continued to impress, landing two big hooks followed by a brilliant right hand, and another strong punch saw Billam-Smith enter the fifth round with a cut by his eye.
The Mexican fended off a jab in the sixth to land a strong combination shot and landed a quick hit to Billam-Smith's bloody eye in the seventh before unleashing a brilliant left hook.
Both boxers exchanged heavy blows to the face in the eighth before the Briton landed two tidy right hits to Ramirez's cheek.
But Ramirez remained in full control in the final stages and was a comfortable winner with all three judges.
