UK light-heavyweight Buatsi made a winning yet unimpressive debut to life under new promoters with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a tight ten-round contest at the Co-op Live Arena.
But the challenger found success, landing some telling clean blows in a contest where the approaches never quite clicked, with excessive holding spoiling the action.
The scoring judges judged it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my best showing but how do champions respond? They prevail," the victor commented in the ring as he was faced boos from the spectators.
The British fighter bounced back after his maiden career setback - an epic battle with his previous opponent in last winter - to earn a twentieth professional win.
Some ringside observers felt Parker, 31, should have been awarded the win but the contender suffered the second setback of his 28-fight professional journey.
Buatsi Claims Triumph in Slow Match
Buatsi's progress has stalled in recent times through promotional disputes and considerable time of inactivity.
Previously predicted as the future of British boxing, he now stands trying to realize his potential - maybe in what seems like a last chance - under fresh management.
He began cautiously, with both competitors prepared to take risks in a cagey early stages.
Parker, whose single earlier setback came at the lower weight class against John Ryder in 2022 after breaking his hand mid-fight, was competing in only his second bout at light heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for Buatsi, who utilized a protective stance to barely take the cleaner periods.
The crowd's patience decreased during regular grabbing, with the challenger going down several times during clinches.
The underdog ended stronger, but multiple periods were difficult to score. Although, ex-champion Carl Frampton - providing analysis for the broadcast network - had it significantly in favor for Parker, giving Buatsi just a single round.
Buatsi advances, but with the caliber of hard hitter David Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Homage Motivates Manchester Derby Fight
In the co-main event, Arthur overcame Bradley Rea by close verdict in a excellent Manchester vs Manchester fight to secure the continental belt.
The venue grew hushed for a deeply poignant memorial prior to the bout as a bell ceremony tolled in remembrance of local hero Ricky Hatton, who died 46 years old in recently.
It was the first major televised fight night in the urban center since the passing of Hatton. As the last bell faded, the stillness became a roar of "there's only one Hatton".
The competition inside the ropes equaled the sentiment. The eventual winner was knocked down by a powerful punch directly to the jaw in the second round, standing uncertainly to his feet on the eight count.
But the traditional red equipment of Arthur soon came forward again. Across the ring, Rea - in competitive blue - was injured quickly, noticeable damage developing under his orbital area as the duo traded punishing blows.
The challenger, 27, landed power punches but Arthur, 34, responded in kind with effective uppercuts as the action rarely dropped over the full distance.
The victor barely secured the verdict with official scores of draw, narrow lead and 115-112, but both fighters were relentless and brave, all the qualities their inspiration Hatton represented.
