Dmitry Bivol dethroned Artur Beterbiev as an undisputed light-heavyweight champion in a thrilling contest in Riyadh in the early hours of Sunday.
Four months after their first classic encounter, 34-year-old Bivol won a majority points decision against his Russian compatriot, six years his senior.
It was Beterbiev's first defeat in 22 pro fights but Bivol was a worthy winner after two judges gave him the decision by 116-112 and 115-113 with the third seeing it as a 114-114 draw.
"I didn't have as much pressure like last time. I just wanted to work from the first round until the end of the 12th. I did enough," said Bivol who never looked back after dominating the early rounds.
"I was better, I was pushing myself more, I was more confident, I was lighter, I was just wanted to win so much today.
"I just told myself he could start from the beginning to destroy me and disturb me, it was hard to keep him distanced over the first four rounds. I was tired but he was tired also."
STAND-IN BAKOLE BEATEN
Meanwhile, Congo fighter Martin Bakole's dream of pulling off a stunning heavyweight victory over New Zealand's Joseph Parker on just two days' notice was shattered.
Bakole only received the call to replace IBF champion Daniel Dubois for the fight in the Saudi capital on Thursday.
The 31-year-old arrived in the early hours of Saturday morning and the lumbering heavyweight quickly discovered the perils of not having time to adequately prepare or train.
The African was dropped in the second round from a sharp right from Parker before the mismatch was stopped.
Dubois withdrew from facing Parker on Thursday through illness.
At that time, Bakole was in the Congo working to close a deal on a new home.
Once financial terms were agreed, he grabbed a flight to Ethiopia and then on to the Gulf.
"I want to thank the people of Saudi Arabia and my team. Martin Bakole, thank you very much for accepting the invitation and for giving me a good fight," Parker told DAZN.
Bakole wasn't the only fighter climbing into the Riyadh ring at short notice.
Four days ago, Josh Padley, electrician by day, boxer by night, was fitting solar panels on a house in Sheffield in northern England.
But after Floyd Schofield was forced to withdraw from his WBC world light heavyweight clash with Shakur Stevenson, the call went out to 29-year-old Padley.
"Monday and Tuesday I was trawling through lofts in Sheffield installing solar panels," Padley told a BBC podcast.
"I went home that night from my day job and the call was there. We rang our nutritionist to make sure we could make the weight safely on such short notice and then we had to do a check weight before we even booked the flight.
"We jumped in my little Ford Transit with 120 000 miles on the clock and headed out to Manchester airport to jump on a plane."
American fighter Stevenson went into Saturday's bout undefeated with 22 wins, having won world titles at super-featherweight, featherweight and lightweight.
Padley fought gamely but the fight was stopped in the ninth round after the Englishman was dropped to the canvas for a third time.