British light heavyweight Buatsi earned a win yet underwhelming beginning to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a split decision in a close ten-round contest at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful clean blows in a contest where the approaches failed to mesh, with constant grabbing marring the contest.
The officials scored it 96-94 in favor to the winner, with the third a 95-95.
"It wasn't my greatest showing but what defines champions? They succeed," Buatsi commented in the ring as he was greeted with boos from the crowd.
The British fighter bounced back after his maiden career setback - an epic battle with Callum Smith in last winter - to claim a 20th pro success.
Several boxing experts thought Parker, thirty-one, deserved the victory but the contender endured the second setback of his 28-fight professional journey.
Buatsi Earns Win in Uneventful Affair
The fighter's advancement has stalled in recent years through contract problems and long spells of lack of fights.
Once tipped as the rising talent of the British fight scene, he now finds himself trying to realize his potential - perhaps in what appears to be a last chance - under recent support.
He started carefully, with neither fighter ready to be aggressive in a cagey opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against John Ryder in 2022 after suffering a hand injury during the bout, was making just his second fight at the higher weight class.
By the fight's midpoint, Parker had made it competitive, making life awkward for the favorite, who worked behind a tight guard to barely take the cleaner rounds.
The crowd's patience wore thin because of frequent holding, with the challenger going down several times during clinches.
Parker finished the stronger, but many rounds were difficult to score. Nevertheless, ex-champion Carl Frampton - providing analysis for Dazn - had it particularly wide for Parker, scoring for Buatsi just a single round.
Buatsi advances, but with the presence of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still looks steep.
Hatton Memorial Inspires All-Manchester Fight
In the secondary fight, Arthur defeated Rea by divided decision in a excellent local rivalry fight to capture the European light heavyweight title.
The venue became quiet for a profoundly moving homage before the fight as ten bells sounded in honor of Manchester's own Hatton, who succumbed 46 years old in last month.
It was the first major televised match card in the location since the passing of Hatton. As the final chime disappeared, the quiet became a shout of "only one Ricky Hatton".
The competition during the bout matched the sentiment. Arthur was floored by a left hook flush on the face in the second round, rising shakily to his footing on the eight count.
But the red-colored attire of Arthur soon advanced again. Across the ring, Rea - in opposing blue - was damaged soon, noticeable damage appearing under his face as the pair exchanged punishing blows.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, fought fire with fire with powerful upward punches as the pace hardly diminished over twelve rounds.
Arthur barely secured the decision with judges scorecards of draw, narrow lead and wider gap, but each competitor were persistent and brave, everything their idol the legend stood for.
