Wladimir Klitschko won a unanimous decision over David Haye, adding the WBA title to his heavyweight haul on Saturday.
The victory in a rain-soaked football stadium in Hamburg means Klitschko and his older brother, Vitali, hold all three major heavyweight titles.
Wladimir already had the IBF title (and minor WBO, IBO belts), while Vitali was the WBC champion.
Klitschko dominated almost from the opening bell against Haye - a smaller fighter who took few chances - winning for the 14th straight time and improving to 17-2 in title fights. But he never knocked Haye down in a bout that did not live up to its advance hype.
"He was scared to fight me," Klitschko said. "I was expecting more of a challenge in the ring, but he was super defensive."
All three judges gave it to Klitschko, scoring the 12-round showdown 117-109, 118-108 and 116-110.
The 35-year-old Klitschko improved to 56-3 (49 KOs), while Haye dropped to 25-2 (23 KOs). The 30-year-old British fighter's only previous loss was in 2004, when he was knocked out by countryman Carl Thompson in a cruiserweight fight.
Haye, who stirred most of the hype with often crass trash-talking, said he hurt a toe on his right foot in training three weeks ago and lost some of his explosive power because of it.
"I couldn't give everything I needed to, it was really frustrating," Haye said in the ring. "I had to knock him out and unfortunately I couldn't do it."
Just to prove it, Haye stood on a table during the post-fight news conference and showed his swollen right foot to Klitschko and dozens of journalists.
"There was a bee that bit you?" Klitschko joked, and advised Haye to avoid appearing like "a sore loser."
Haye slipped to the canvas repeatedly as he got into clinches with the heavier, taller and more experienced Ukrainian, who was fighting in his home base.
Referee Genaro Rodriguez finally had enough of it and gave Haye a count when he slipped in the 11th round. This time, Haye got quickly to his feet. In the seventh, Klitschko had a point deducted for pushing Haye to the canvas.
Haye came out slugging in the final round, landing a series of body punches and a good right to the head. But Klitschko came right back with some stinging jabs and right hands to take away one of the rare offensive threats of the night from the British fighter.
Klitschko wanted to knock Haye out, disgusted with the Brit's trash talking over the past few years. The fact that he didn't disappointed him, though he was happy to join the major titles with his brother, who he has said he will never fight.
"We're celebrating with my brother that we've collected all the belts in the heavyweight division," Klitschko said. "It wasn't as spectacular as I expected, but I was trying."
For most of the fight, Klitschko stayed behind his feared left jab. He landed a right on Haye's chin in the fifth but the Brit recovered nicely, bouncing off the ropes to stay on his feet.
Haye fought defensively for the most part, unwilling to risk going inside and catching a Klitschko right to the head. He took off his shoe in the ring to show off a toe he said he broke three weeks ago that bothered him the entire fight.
"He's big, strong and very effective at what he does," Haye said. "It was definitely subpar for me."
The fight failed to live up to its enormous buildup. The fast-punching Englishman had been seen as the biggest threat to the Klitschko clan's grip on the heavyweight division, but previous attempts to arrange a showdown failed.
A potential fight against Vitali in London was scrapped, and Haye pulled out of a fight last year with Wladimir, citing a back injury.
Before the fight the Englishman was adamant that he would retire on Oct. 13, his 31st birthday. After it, he wasn't so sure.
"I have to sit down and have a good think about what I'm going to do next," Haye said. "It would be disappointing to finish on a loss, particularly when I know I wasn't firing on all cylinders tonight."