Billy Joe Saunders won a tactical battle with Andy Lee to become Britain's 12th reigning world champion with a majority points decision win on Saturday.
Irishman Lee lost the WBO middleweight title in a first defence after being floored by two right hooks in the third round and then failing to trouble Saunders who won by scores of 114-112, 115-111 to 113-113 at the Manchester Arena.
Saunders (23-0, 12 KOs) prevailed after Lee (34-3-1, 24 KOs) piled on the pressure late on but failed to find the knockout blow he needed.
Hatfield's unbeaten Saunders made a stunning start and floored Irishman Lee twice with clean right hooks in the third round. Lee has recovered from losing positions in his previous two fights but was unable to claw back the lead Saunders created from a fast start.
"I kept thinking about Lee's fight with Matt Korobov, and I thought I won't rush and I will recuperate, if you take lead hand away from him you can beat him," Saunders said.
"I kept trying to draw him on and draw him on, I know he had to come after I put him down twice and that's when I had all the time in the world."
It was supposed to be Lee with the power punches but Saunders threw his right hands with impeccable timing.
Lee recovered quickly on both occasions and then won the fourth round by dictating behind his jab. But Saunders was better in the fifth and landed a big swinging left on Lee, who was behind on points at the halfway stage.
Lee has come back from losing positions before to win fights with one-punch finishes, but Saunders kept him at bay with neat boxing in rounds six and seven.
Both are southpaws and they cancelled each other out in some of the later rounds and Lee was left looking for a KO in the later rounds.
Lee was more polished in the last three rounds and was dangerous in the 12th as he tried to make up for being twice decked in the third.
But Saunders had done enough to earn the decision and become Britain's 12th world champion and the second from the traveller community after Tyson Fury won the WBA-IBF-WBO world heavyweight titles last month.
Defeat in his first defence of the WBO belt cost Lee a shot at world No 1 Gennady Golovkin, who Saunders is expected to avoid in 2016.
"He was an Olympian at 18 years old and won British, Commonwealth and European titles and he's now world champion but he needs to stay focused and don't let this good work go to waste," said promoter Frank Warren.
"If Chris Eubank Jr wants to fight for the British title, let him do that, Billy is world champion."