UK light heavyweight Buatsi made a winning yet underwhelming start to his career under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's work rate likely gained him a split decision in a close ten-round bout at the boxing arena.
But the challenger found success, landing some telling single shots in a fight where the approaches failed to mesh, with constant grabbing disrupting the contest.
Two judges scored it 96-94 for to the winner, with the third a 95-95.
"It wasn't my finest performance but what defines champions? They succeed," the victor stated in the ring as he was faced disapproval from the crowd.
The British fighter got back to winning after his initial pro loss - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Various analysts thought Parker, thirty-one, merited the win but the British boxer experienced the second loss of his 28-match professional journey.
Buatsi Secures Win in Uneventful Match
Buatsi's progress has plateaued in the past few years through promotional disputes and extended periods of lack of fights.
Previously predicted as the future of the British fight scene, he now finds himself trying to fulfil that early promise - possibly in what appears to be a final roll of the dice - under recent support.
He began cautiously, with neither fighter willing to be aggressive in a cagey early stages.
The challenger, whose only previous defeat came at super middleweight against his former opponent in 2022 after damaging his hand mid-fight, was making just his second fight at light heavyweight.
By the fight's midpoint, Parker had kept it close, causing problems for the favorite, who operated with a solid defense to narrowly win the better rounds.
The audience's tolerance decreased because of regular grabbing, with the challenger falling to the floor multiple occasions during grappling.
Parker finished the stronger, but several stanzas were difficult to score. Nevertheless, ex-champion Carl Frampton - commentating on Dazn - had it strongly leaning for Parker, awarding Buatsi just only one stanza.
Buatsi advances, but with the presence of hard hitter Benavidez, and Russian champion Bivol leading the category, the road to world glory - based on this performance - still appears challenging.
Hatton Memorial Motivates Manchester Derby Battle
In the co-main event, Lyndon Arthur overcame Rea by split-decision in a outstanding Manchester vs Manchester battle to secure the European light-heavyweight title.
The stadium became quiet for a deeply poignant tribute prior to the bout as a bell ceremony rang in remembrance of the city's native Hatton, who succumbed aged 46 in last month.
It was the initial significant broadcast match card in the urban center since the passing of Hatton. As the final chime faded, the silence gave way to a shout of "there's just one Ricky Hatton".
The competition during the bout reflected the sentiment. The eventual winner was floored by a significant blow directly to the jaw in the early round, rising shakily to his feet on the eight count.
But the red-colored equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in opposing blue - was damaged quickly, significant bruising developing under his face as the fighters exchanged hard punches.
Rea, 27, delivered effective strikes but Arthur, thirty-four, fought fire with fire with stinging uppercuts as the action hardly diminished over the full distance.
The victor barely secured the verdict with official scores of 114-114, close margin and wider gap, but the two athletes were persistent and courageous, all the qualities their idol Hatton stood for.
