UK light-heavyweight Buatsi made a winning yet unimpressive debut to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a split decision in a close ten-round fight at the boxing arena.
But Parker landed significant shots, landing some telling individual punches in a fight where the techniques failed to mesh, with constant grabbing spoiling the fight.
Two judges judged it 96-94 to the winner, with the final judge a even score.
"It wasn't my greatest performance but what defines champions? They prevail," the victor said in the arena as he was greeted with negative reactions from the crowd.
The Londoner bounced back after his maiden career setback - an epic battle with his previous opponent in last winter - to secure a 20th career victory.
Various analysts believed Parker, thirty-one, should have been awarded the decision but the contender experienced the second defeat of his 28-bout career.
Buatsi Secures Victory in Dull Encounter
The fighter's advancement has plateaued in recent years through contract problems and considerable time of inactivity.
Once tipped as the future of British boxing, he now finds himself trying to realize his potential - maybe in what appears to be a ultimate opportunity - under recent support.
He started carefully, with neither fighter ready to be aggressive in a tentative opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was making just his second bout at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, creating difficulties for Buatsi, who utilized a protective stance to narrowly win the cleaner periods.
The crowd's patience decreased amid frequent holding, with the challenger slipping to the canvas various instances during clinches.
The underdog closed well, but multiple periods were challenging to assess. Nevertheless, former world champion Carl Frampton - working with the broadcast network - had it particularly wide for the challenger, giving Buatsi just one round.
Buatsi progresses, but with the presence of hard hitter Benavidez, and Russian star Bivol leading the category, the road to world glory - based on this performance - still appears challenging.
Hatton Homage Fuels Manchester Derby Fight
In the supporting bout, Arthur defeated Rea by divided decision in a outstanding Manchester vs Manchester fight to capture the European light heavyweight championship.
The venue became quiet for a deeply poignant homage ahead of the contest as ten bells rang in honor of the city's native Hatton, who passed away aged 46 in recently.
It was the first major televised fight night in the urban center since the passing of Hatton. As the concluding sound ended, the quiet became a shout of "there's just one Ricky Hatton".
The competition during the bout matched the feeling. Arthur was floored by a powerful punch directly to the jaw in the second round, standing uncertainly to his position on the referee's count.
But the red-colored equipment of Arthur soon came forward again. From the other corner, the opponent - in rival City blue - was injured quickly, noticeable damage developing under his orbital area as the duo traded powerful shots.
The challenger, 27, landed power punches but Arthur, 34, fought fire with fire with effective uppercuts as the action rarely dropped over 12 rounds.
The victor narrowly won the decision with official scores of draw, 115-113 and wider gap, but both fighters were relentless and brave, exactly what their idol Hatton stood for.
