Artur Beterbiev beat Dmitry Bivol by a majority 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.
In the end, two ringside judges scored it 115-113, 116-112 for Beterbiev, with a third judge scoring it as a 114-114 draw. (The Guardian had it 114-114.)
The headline clash at the Saudi capital’s Kingdom Arena, postponed from June after Montreal-based Beterbiev suffered a knee injury, put all four major world titles – WBO, WBA, IBF and WBC – in the hands of one man for the first time.
The last undisputed light-heavyweight champion was the Russian-American Roy Jones Jr who beat Reggie Johnson to unify the WBA, WBC and IBF belts in 1999.
Bivol made himself a moving target in a high-quality fight between the big punching and aggressive Beterbiev and a more fluid rival who landed eye-catching early blows and had the better of the early rounds.
There was little between the two at the half-way point, with Beterbiev possibly behind but every round a close call in a fight short of fireworks but with plenty for the purists.
Beterbiev knew he had to close with a bang in the last two rounds and raised the tempo but Bivol hung in there and fired back some powerful combinations.
“I just congratulate Artur and his team, he deserves it,” said Bivol, looking forward also to a possible rematch.
“I did my job, I felt I could do better, I always feel I can do better, but that’s the opinion of the judges. He won.”
Australia’s Jai Opetaia earlier retained his IBF cruiserweight world title when Jack Massey’s corner threw in the towel two minutes into the sixth round with the beaten Briton bleeding from a cut to the side of his nose.
The convincing win took Opetaia’s record to 26-0.
Unbeaten Australian Skye Nicolson won the first women’s world title fight held in Saudi Arabia when she defended her WBC featherweight belt against Britain’s Raven Chapman in a unanimous points decision.
A light heavyweight fight between Britons Ben Whittaker and Liam Cameron ended in a draw after both crashed out of the ring, while Fabio Wardley stopped Frazer Clarke in the first round of their British heavyweight title fight.