British light heavyweight Buatsi earned a win yet underwhelming start to his career under new promoters with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a competitive 10-round contest at the Co-op Live Arena.
But Parker landed significant shots, landing some telling clean blows in a contest where the styles never quite clicked, with constant grabbing marring the action.
The scoring judges judged it 96-94 in favor to Buatsi, with the final judge a 95-95.
"It wasn't my greatest showing but how do champions respond? They succeed," the victor stated in the ring as he was greeted with negative reactions from the crowd.
The Londoner bounced back after his initial pro loss - an epic battle with his previous opponent in last winter - to secure a 20th career victory.
Several boxing experts felt Parker, thirty-one, should have been awarded the decision but the British boxer endured the second loss of his 28-fight professional journey.
The Champion Claims Win in Dull Affair
His career development has plateaued in the past few years through promotional disputes and considerable time of lack of fights.
Previously predicted as the rising talent of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under fresh management.
He opened tentatively, with neither fighter willing to take risks in a calculated early stages.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was competing in only his second bout at light-heavyweight.
By the middle rounds, Parker had kept it close, making life awkward for the favorite, who operated with a tight guard to narrowly win the better periods.
The audience's tolerance decreased amid regular grabbing, with Parker going down several times during close exchanges.
Parker closed well, but many rounds were challenging to assess. However, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it particularly wide for the challenger, awarding Buatsi just a single round.
Buatsi progresses, but with the caliber of power puncher David Benavidez, and Eastern European fighter Bivol dominating the weight class, the road to world glory - based on this performance - still seems difficult.
Hatton Homage Fuels Manchester Derby Fight
In the supporting bout, Lyndon Arthur defeated Bradley Rea by split-decision in a terrific Manchester vs Manchester contest to capture the continental championship.
The venue grew hushed for a profoundly moving homage ahead of the contest as ten bells tolled in remembrance of the city's native Hatton, who died at age 46 in recently.
It was the initial significant broadcast match card in the location since Hatton's death. As the concluding sound disappeared, the quiet became a roar of "there's just one Hatton".
The fighting within the ring equaled the sentiment. The eventual winner was floored by a left hook flush on the jaw in the second round, getting up unsteadily to his position on the eight count.
But the traditional red shorts of the fighter soon came forward again. Across the ring, Rea - in rival City blue - was injured quickly, significant bruising forming under his face as the pair traded powerful shots.
Rea, 27, connected with strong blows but Arthur, 34, fought fire with fire with stinging uppercuts as the action hardly diminished over 12 rounds.
The victor narrowly won the verdict with judges scorecards of draw, close margin and 115-112, but both fighters were relentless and brave, exactly what their inspiration Hatton represented.
