British light heavyweight Buatsi made a winning yet unimpressive start to life under fresh promotional backing with a points victory 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 Co-op Live Arena.
But the challenger had his moments, landing some telling individual punches in a contest where the techniques didn't complement each other, with frequent clinching spoiling the action.
The officials scored it 96-94 to the winner, with the remaining official a even score.
"It wasn't my best showing but what do champions do? They succeed," Buatsi said in the ringside as he was greeted with negative reactions from the crowd.
The British fighter returned to winning ways after his first professional defeat - an epic battle with his previous opponent in February - to claim a 20th pro success.
Various analysts thought Parker, thirty-one, deserved the victory but the contender endured the second defeat of his 28-bout professional journey.
The Champion Claims Triumph in Slow Match
The fighter's advancement has stalled in recent times through management issues and extended periods of lack of fights.
Earlier forecast as the next star of British boxing, he now is positioned trying to realize his potential - possibly in what feels like a last chance - under fresh management.
He started carefully, with the two boxers ready to be aggressive in a calculated opening few 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 participating in his second bout at the higher weight class.
By the fight's midpoint, Parker had stayed in contention, making life awkward for Buatsi, who worked behind a tight guard to narrowly win the better periods.
The audience's tolerance wore thin because of constant clinching, with the challenger falling to the floor several times during close exchanges.
Parker ended stronger, but several stanzas were hard to judge. Although, ex-champion Carl Frampton - commentating on Dazn - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
Buatsi progresses, but with the caliber of hard hitter Benavidez, and Eastern European fighter Bivol leading the category, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Memorial Motivates Local Rivalry Contest
In the co-main event, Arthur beat Bradley Rea by divided decision in a excellent Manchester vs Manchester contest to capture the European light heavyweight belt.
The stadium became quiet for a profoundly moving homage prior to the bout as 10 bells sounded in remembrance of the city's native Ricky Hatton, who died at age 46 in recently.
It was the initial significant broadcast fight night in the city since the passing of Hatton. As the concluding sound ended, the quiet transitioned to a roar of "there's just one Hatton".
The fighting inside the ropes equaled the feeling. Arthur was floored by a powerful punch directly to the chin in the early round, rising shakily to his footing on the referee's count.
But the Manchester United-red equipment of Arthur soon pressed ahead again. On the opposite side, Rea - in rival City blue - was damaged quickly, heavy swelling forming under his eye as the pair landed punishing blows.
The challenger, twenty-seven, connected with strong blows but the champion, 34, fought fire with fire with effective uppercuts as the action hardly diminished over twelve rounds.
The victor edged the result with scoring tallies of draw, 115-113 and wider gap, but each competitor were determined and courageous, exactly what their inspiration the legend stood for.
