Artur Beterbiev beat Dmitry Bivol by a points decision to become the first undisputed light heavyweight champion in the division for more than 20 years.
The 39-year-old Beterbiev (21-0, 20 KOs) had won all 20 of his previous fights by knockout but was forced the distance by his fellow Russian rival in Riyadh in the early hours of Sunday morning in a fight that had several swings of momentum and was almost too close to call.
"I feel not bad," Beterbiev said to DAZN after the fight. "I wanted to box with more quality. I’ll be better one day. It was a little bit uncomfortable."
"Of course, it was a tough fight because Dmitry is a tough champion and he has tough skills, better than me."
Throughout the bout there was never much between the two dominant fighters of the division as Bivol (23-1, 12 KOs) used his speed to land early blows, while Beterbiev warmed to the task in the middle rounds before a late flurry in the final rounds appeared to clinch it.
"During the fight, we always try to change something," Beterbiev said. "I didn’t deliver more punches, I don’t know. Today I am lucky too."
In the end, two judges scored it 115-113, 116-112 for Beterbiev, with a third judge scoring it as a 114-114 draw.
"I am a warrior. I have no explanation because it looks like excuses. I am a warrior," Bivol told DAZN. "I don’t know, I did my job but I felt like I could do better but it was just the opinion of some judges.
"Congratulations to Artur. He is powerful, very powerful. I have a bruise from my hand, he hit it and it was so hard."
It was the first undisputed title fight in the division since 2002 and was the first time all four major world titles — WBO, WBA, IBF and WBC — have been up for grabs in the four-belt era.
They now all belong to Beterbiev.
He came into the bout with the WBC, WBO and IBF light heavyweight titles after defeating Callum Smith by knockout in January, needing just Bivol's WBA belt — which Bivol won with a shock upset points decision over Canelo Alvares in May 2022 — to complete the set.
Both Russians showed patience in the opening rounds before Bivol went to work with his left jab and right hook as his speed began to trouble Beterbiev.
The tide began to turn through the fifth and sixth rounds as Beterbiev began landing his right hook, forcing Bivol onto the defensive.
The bout spurred to life in the seventh as both fighters attacked. A big left by Bivol forced Beterbiev against the ropes, but Beterbiev responded with a heavy jab and short left hook as both fighters ended the round showing damage.
Beterbiev had only been beyond round seven five times in his 20 previous fights, but Bivol was going to make this go the distance here as he was again the more assertive through rounds eight and nine.
But Beterbiev came back again in the 10th with a strong round to leave the fight in the balance and continued the assault into the 11th as a right hook to Bivol’s body was followed by an uppercut in a rare clear round win.
The final round saw Beterbiev up the tempo even more as he sought to extend his incredible record of winning every bout inside the distance. Bivol held on to deny his compatriot a knockout blow but hadn’t done quite enough to clinch it.
Earlier, Australian WBC featherweight champion Skye Nicolson beat Britain’s Raven Chapman by a unanimous points decision in the first-ever women’s world title fight in Saudi Arabia.
