UK light heavyweight Buatsi made a winning yet unimpressive beginning to life under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a split decision in a competitive 10-round contest at the Manchester venue.
But the challenger found success, landing some telling single shots in a match where the styles never quite clicked, with excessive holding marring the action.
The officials judged it 96-94 for to the winner, with the third a 95-95.
"It wasn't my greatest showing but what do champions do? They prevail," Buatsi said in the arena as he was met by negative reactions from the spectators.
The Londoner got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to earn a 20th career victory.
Several boxing experts believed the challenger, thirty-one, should have been awarded the victory but the contender suffered the second defeat of his 28-bout career.
The Champion Claims Triumph in Uneventful Encounter
The fighter's advancement has stalled in recent times through management issues and considerable time of inactivity.
Previously predicted as the next star of UK boxing, he now stands trying to realize his potential - possibly in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors ready to take risks in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after breaking his hand during the bout, was making just his second appearance at light heavyweight.
By the fight's midpoint, Parker had stayed in contention, causing problems for the favorite, who utilized a protective stance to edge the cleaner stanzas.
The audience's tolerance decreased amid constant clinching, with the challenger slipping to the canvas several times during clinches.
Parker finished the stronger, but several stanzas were difficult to score. Nevertheless, former world champion the boxing analyst - commentating on Dazn - had it particularly wide for the challenger, awarding Buatsi just only one stanza.
Buatsi moves on, but with the caliber of power puncher Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - judging by this showing - still appears challenging.
Ricky Hatton Memorial Inspires Local Rivalry Battle
In the co-main event, Arthur defeated Rea by split-decision in a excellent Manchester vs Manchester fight to capture the European light heavyweight title.
The venue fell silent for a deeply poignant tribute prior to the bout as 10 bells rang in remembrance of local hero Hatton, who succumbed at age 46 in September.
It was the first major televised match card in the urban center since Hatton's death. As the concluding sound disappeared, the quiet transitioned to a shout of "there's only one Hatton".
The fighting within the ring equaled the feeling. The eventual winner was sent to the canvas by a significant blow squarely on the jaw in the second round, getting up unsteadily to his position on the referee's count.
But the traditional red equipment of the fighter soon came forward again. On the opposite side, the opponent - in competitive blue - was injured early, noticeable damage appearing under his eye as the pair exchanged punishing blows.
Rea, twenty-seven, connected with strong blows but the champion, thirty-four, matched the intensity with powerful upward punches as the pace hardly diminished over 12 rounds.
The victor edged the result with judges scorecards of draw, close margin and 115-112, but each competitor were relentless and full of heart, everything their inspiration the legend represented.
