UK light-heavyweight Buatsi secured a victory yet unimpressive beginning to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a close ten-round contest at the Co-op Live Arena.
But the challenger had his moments, delivering effective clean blows in a fight where the styles failed to mesh, with excessive holding spoiling the fight.
The officials judged it 96-94 to the winner, with the remaining official a 95-95 draw.
"It wasn't my best showing but how do champions respond? They prevail," the victor stated in the ring as he was greeted with boos from the crowd.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to secure a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the decision but the British boxer experienced the second loss of his 28-match career.
Buatsi Earns Triumph in Dull Match
His career development has slowed in the past few years through management issues and extended periods of lack of fights.
Previously predicted as the future of British boxing, he now is positioned trying to achieve expectations - perhaps in what feels like a last chance - under recent support.
He began cautiously, with both competitors willing to overcommit in a tentative early stages.
The challenger, whose only previous defeat came at the lower weight class against his former opponent in 2022 after suffering a hand injury mid-fight, was competing in only his second appearance at light heavyweight.
By the middle rounds, Parker had stayed in contention, causing problems for the favorite, who operated with a protective stance to edge the cleaner periods.
The audience's tolerance diminished during frequent holding, with the challenger going down several times during close exchanges.
Parker finished the stronger, but many rounds were hard to judge. However, ex-champion Carl Frampton - commentating on Dazn - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
The victor progresses, but with the likes of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Memorial Inspires Manchester Derby Fight
In the secondary fight, Lyndon Arthur overcame Bradley Rea by close verdict in a outstanding all-Manchester contest to secure the continental championship.
The stadium grew hushed for a deeply poignant homage prior to the bout as ten bells rang in memory of the city's native Hatton, who succumbed at age 46 in recently.
It was the first major televised fight night in the location since the passing of Hatton. As the last bell faded, the stillness became a roar of "there's only one Hatton".
The competition during the bout reflected the feeling. The eventual winner was knocked down by a left hook squarely on the face in the initial stage, standing uncertainly to his position on the count of eight.
But the red-colored equipment of the fighter soon pressed ahead again. On the opposite side, Rea - in opposing blue - was marked up early, heavy swelling forming under his orbital area as the fighters exchanged hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, matched the intensity with effective uppercuts as the intensity rarely dropped over twelve rounds.
The victor narrowly won the decision with scoring tallies of draw, narrow lead and clearer margin, but each competitor were determined and full of heart, everything their idol Hatton embodied.
