British light-heavyweight Buatsi secured a victory yet unimpressive beginning to his career under fresh promotional backing with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a tight ten-round fight at the Manchester venue.
But the challenger found success, landing some telling single shots in a contest where the techniques failed to mesh, with excessive holding spoiling the fight.
Two judges scored it 96-94 to the winner, with the final judge a 95-95 draw.
"It wasn't my greatest showing but what defines champions? They prevail," the victor commented in the arena as he was faced boos from the spectators.
The Londoner got back to winning after his maiden career setback - an memorable fight with Callum Smith in last winter - to earn a twentieth professional win.
Some ringside observers thought Parker, 31, should have been awarded the victory but the contender experienced the second setback of his 28-bout career.
Buatsi Secures Triumph in Dull Match
Buatsi's progress has plateaued in recent years through contract problems and extended periods of inactivity.
Earlier forecast as the future of the British fight scene, he now finds himself trying to achieve expectations - maybe in what seems like a ultimate opportunity - under fresh management.
He began cautiously, with neither fighter ready to overcommit in a tentative opening few rounds.
Parker, whose single earlier setback came at super-middleweight against John Ryder in 2022 after breaking his hand during the bout, was making just his second fight at light-heavyweight.
By the halfway stage, the underdog had made it competitive, causing problems for the favorite, who utilized a tight guard to narrowly win the better stanzas.
The crowd's patience decreased because of regular grabbing, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog closed well, but several stanzas were difficult to score. Although, ex-champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
The victor moves on, but with the presence of power puncher Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still looks steep.
Ricky Hatton Homage Motivates All-Manchester Battle
In the supporting bout, Lyndon Arthur beat Bradley Rea by divided decision in a outstanding Manchester vs Manchester fight to win the continental championship.
The arena grew hushed for a deeply poignant homage prior to the bout as ten bells rang in memory of the city's native Ricky Hatton, who passed away at age 46 in September.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the last bell faded, the quiet became a chant of "there's just one Hatton".
The competition inside the ropes matched the emotion. The eventual winner was knocked down by a significant blow directly to the jaw in the second round, getting up unsteadily to his feet on the eight count.
But the red-colored equipment of the fighter soon came forward again. From the other corner, Rea - in competitive blue - was damaged soon, significant bruising appearing under his orbital area as the pair landed powerful shots.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with stinging uppercuts as the pace seldom decreased over the full distance.
The victor edged the result with judges scorecards of draw, 115-113 and wider gap, but the two athletes were persistent and courageous, everything their idol the legend represented.
