UK light heavyweight Buatsi secured a victory yet unimpressive debut to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a majority decision in a tight 10-round contest at the Manchester venue.
But Parker had his moments, delivering effective clean blows in a contest where the techniques didn't complement each other, with frequent clinching disrupting the action.
The scoring judges scored it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my greatest showing but what defines champions? They prevail," Buatsi said in the ring as he was greeted with disapproval from the spectators.
The Londoner got back to winning after his initial pro loss - an epic battle with Callum Smith in last winter - to earn a 20th pro success.
Various analysts believed Parker, thirty-one, deserved the decision but the Derbyshire fighter experienced the second setback of his 28-bout career.
Buatsi Claims Triumph in Dull Affair
Buatsi's progress has slowed in recent years through promotional disputes and long spells of lack of fights.
Earlier forecast as the future of the British fight scene, he now finds himself trying to fulfil that early promise - perhaps in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors prepared to take risks in a calculated opening few rounds.
The challenger, whose only previous defeat came at super middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was participating in his second appearance at light heavyweight.
By the middle rounds, the underdog had kept it close, causing problems for the favorite, who utilized a protective stance to barely take the better stanzas.
The spectators' acceptance wore thin amid constant clinching, with Parker slipping to the canvas various instances during clinches.
Parker closed well, but multiple periods were hard to judge. Although, former world champion the boxing analyst - commentating on Dazn - had it strongly leaning for Parker, awarding Buatsi just a single round.
Buatsi moves on, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol leading the category, the path to championship success - on this evidence - still looks steep.
Hatton Homage Motivates All-Manchester Contest
In the supporting bout, Lyndon Arthur overcame Rea by close verdict in a excellent Manchester vs Manchester contest to win the European light heavyweight title.
The venue grew hushed for a extremely emotional tribute before the fight as ten bells tolled in honor of Manchester's own Ricky Hatton, who succumbed 46 years old in last month.
It was the premier televised boxing event in the urban center since the passing of Hatton. As the concluding sound ended, the quiet gave way to a roar of "only one Ricky Hatton".
The competition inside the ropes reflected the emotion. Arthur was floored by a powerful punch directly to the chin in the initial stage, getting up unsteadily to his position on the eight count.
But the red-colored attire of the fighter soon pressed ahead again. From the other corner, Rea - in rival City blue - was injured quickly, heavy swelling appearing under his face as the fighters landed punishing blows.
The challenger, 27, connected with strong blows but the champion, 34, fought fire with fire with effective uppercuts as the action seldom decreased over the full distance.
Arthur barely secured the decision with scoring tallies of draw, narrow lead and wider gap, but both fighters were relentless and full of heart, all the qualities their idol Hatton stood for.
