Junior Witter won the vacant WBC light welterweight title with a unanimous points victory over DeMarcus Corley at Alexandra Palace, London on Friday.
Bradford's Witter, 32, gave a lesson in counter-punching and landed the bigger shots throughout the contest.
He had his American opponent in serious trouble in round five with a huge right hand and again in round six.
Witter, who lost his last world title shot in 2000, won 117-111, 118-112 and 116-113 on the judges' scorecards.
It was a sweet reward for the Briton, who had won 18 fights and claimed the British, Commonwealth and European titles since his defeat to Zab Judah in an IBF contest more than six years ago.
"Now I am world champion, and I am on top of the world," said Witter.
"I was up against a hell of a fighter, with a great chin. But it was just a case of making sure I won, and I never felt in any trouble whatsoever.
"A lot of people did not have faith in me - but I have proved them all wrong"
"Once he felt the power, he didn't want to risk it too much and it allowed me to stay on the outside and pick him off.
"Every time he came close I managed to catch him with a shot and I wobbled him and he touched down a couple of times.
"A lot of people did not have faith in me, from before I turned pro - but I have proved them all wrong."
Witter started the fight as he meant to go on, keeping his distance and picking Corley off with flurries in the opening few rounds.
In round four Witter introduced some bizarre posturing, his leading arm cocked as if to tempt Corley in, and it seemed to faze the Washington DC native.
In the fifth, Corley was rocked by a thunderous roundhouse right from Witter and did well to stay upright.
With Corley's legs sagging, Witter moved in for the kill and sent his opponent to the canvas, but the referee adjudged that Corley had slipped.
Witter tried to build on his initiative in the next round, landing a crashing right hook and a clean overhand left.
Corley, also 32, showed tremendous heart to remain on his feet but it was clear the wind had been knocked out of him.
There was a moment of farce in round seven when both fighters stood perfectly still for more than 10 seconds, and it was clear Corley was growing more and more frustrated.
With the fight virtually in the bag by round nine, Witter was content to coast the final quarter of the fight. And although Corley's corner held their charge aloft at the final bell, it was clear that Witter had won by a considerable margin.
With the WBC title in the bag, Witter should now have a raft of options open to him.
While Witter's cagey style is an acquired taste, American legend Oscar de la Hoya, in his role as promoter, is apparently keen to work with him in the States.
But the fight everyone wants to see is against domestic rival and former 140lbs king Ricky Hatton, who fights for the IBF belt again in January.
Witter's promoter Mick Hennessy said he is looking to make the fight "next spring or early summer", possibly at Manchester City's ground.
On the undercard, 21-year-old John Murray extended his unbeaten record to 18 bouts by beating Moebi Sarouna of Togo on points. The Manchester super featherweight fights Scotland's Ricky Burns in a British title eliminator on 14 October.
London's Darren Barker, gold medallist at the 2002 Commonwealth Games, won the Southern Area middleweight title with a points win over Hussain Osman.