Gilberto Ramirez produced a blistering display to beat Chris Billam-Smith and become the unified WBA and WBO cruiserweight world champion in Saudi Arabia on Saturday night.
The Mexican showcased electric speed and accuracy to conquer the toughness of Billam-Smith in a full-throttle main event, clinching it 116-112, 116-112, 116-113 on the judge's cards.
Victory lifts Ramirez to 47-1 - his only career defeat coming against Dimitry Bivol - while seeing Billam-Smith fall to 20-2 having entered the fight on the back of June's successful title defence against Richard Riakporhe.
Ramirez's agility and timing would prove defining as he out-manoeuvred Billam-Smith impressively while manipulating his angles to find his target consistently throughout the fight.
Billam-Smith continued to come forward in the final stages of a gruelling contest as the two men valiantly traded leather until the final bell, but could not make up the ground earned by Ramirez's earlier dominance.
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"I feel great… I'm a three-weight champion," said Ramirez. "I prepared for a tough guy. Me and my team have been preparing, we knew that he was a tough guy, he was a strong fighter. He was a champion. It was an honour for me and get the belt."
Ramirez had made no secret of his desire to pursue the knockout having faced doubts over his power after coming up from super middleweight. He could now turn his attention towards a blockbuster showdown with IBF world champion Jai Opetaia.
"It's a bit of irony. My initials are obviously CBS and I say consistency builds success and I think the consistency of 'Zurdo' was what won it for him. All respect to him," said Billam-Smith.
"I've a huge amount of respect for him, always have done.
"He was really good, he's got consistent shots, throws threes, fours, fives, then moves and I think I was lacking tonight in tracking him and letting him get his shots off."
Billam-Smith made his physicality known in the opening round with joy behind a lead right hand that had Ramirez in retreat while struggling to swerve the Brit's counters.
Ramirez responded ruthlessly in the second as he capitalised on an opening with a thumping left hand before landing tidy work at the ropes. He then left himself exposed to a crunching right hook from Billam-Smith, before squeezing in a left hook of his own at the bell in an all-action start.
The Mexican timed a smart lead right hand to snap back the head of Billam-Smith in the third, followed by a three-punch combination at the ropes and a vicious left hook only to eat a bruising uppercut of his own as the pair continued to exchange shots.
Ramirez sought to take the fight on the front foot, a feature to Billam-Smith's downfall, and reaped the rewards with another fizzing left hook to capitalise on a drop in his opponent's guard.
Billam-Smith's chin and legs were then put to the test in an enthralling fourth when Ramirez broke through with a rocking right hand that unbalanced him momentarily, superior accuracy and timing continuing to cause more problems and prompting trainer Shane McGuigan to urge his fighter to put his opponent on the back foot.
The hand speed of Ramirez continued to trouble Billam-Smith while attacking a cut on the left eye of his opponent, who at the same time was underlining his well-renowned toughness after taking a barrage of clean shots.
Billam-Smith refused to fade despite the blood trickling from his eye. Ramirez, too, though, persisting in applying the pressure with impressive variation between head and body shots while also showing a willingness to meet his counterpart on the inside.
The combinations began to fly again from Ramirez in the eighth, only for Billam-Smith to stand firm and land a string of right hooks at the end of the round while his opponent was regaining his energy.
As Billam-Smith marched forward, Ramirez answered back with a jab that could not miss with both men breathing heavily upon their return to the corner.
The pair continued to trade flush hooks, almost simultaneously, in a frantic final round, Ramirez pinning Billam-Smith into the corner and unloading another flurry in a bid to ice the performance. As they continued to slug it out, the Mexican fans in the crowd were already celebrating in anticipation of a Ramirez win.
With 30 seconds to go, Billam-Smith clubbed Ramirez into the ropes, with hands flailing in all directions and both maintaining the same ferocious tempo until the final bell, at which point they would fall into each other's arms in recognition of a thrilling duel.
Watch IBF welterweight champion Natasha Jonas take on WBC titlist Ivana Habazin at the Liverpool Exhibition Centre on December 14, live on Sky Sports