UK light heavyweight Buatsi earned a win yet unimpressive debut to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a majority decision in a tight 10-round contest at the boxing arena.
But Parker had his moments, landing some telling individual punches in a match where the approaches failed to mesh, with constant grabbing marring the contest.
The scoring judges scored it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my best showing but how do champions respond? They win," the victor commented in the arena as he was greeted with disapproval from the audience.
The Londoner returned to winning ways after his first professional defeat - an epic battle with his previous opponent in February - to secure a twentieth professional win.
Some ringside observers thought Parker, thirty-one, deserved the win but the Derbyshire fighter experienced the second loss of his 28-fight professional journey.
The Champion Claims Victory in Uneventful Affair
Buatsi's progress has plateaued in recent times through management issues and extended periods of lack of fights.
Once tipped as the future of British boxing, he now stands trying to realize his potential - possibly in what seems like a last chance - under fresh management.
He started carefully, with neither fighter ready to overcommit in a cagey opening few rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was participating in his second bout at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, causing problems for Buatsi, who operated with a tight guard to edge the cleaner stanzas.
The spectators' acceptance decreased because of regular grabbing, with the challenger going down multiple occasions during close exchanges.
Parker finished the stronger, but multiple periods were difficult to score. However, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
The victor progresses, but with the presence of heavy hitter David Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - judging by this showing - still seems difficult.
Hatton Homage Fuels Manchester Derby Battle
In the co-main event, Arthur overcame Rea by divided decision in a terrific local rivalry battle to capture the European light heavyweight title.
The venue became quiet for a extremely emotional tribute before the fight as ten bells tolled in remembrance of local hero Hatton, who succumbed aged 46 in September.
It was the first major televised fight night in the urban center since Hatton's death. As the concluding sound disappeared, the stillness became a roar of "there's just one Ricky Hatton".
The competition within the ring reflected the feeling. Arthur was knocked down by a powerful punch flush on the jaw in the early round, getting up unsteadily to his feet on the referee's count.
But the Manchester United-red equipment of the fighter soon pressed ahead again. On the opposite side, the opponent - in rival City blue - was marked up quickly, noticeable damage forming under his eye as the duo traded powerful shots.
The challenger, 27, connected with strong blows but the champion, thirty-four, responded in kind with effective uppercuts as the pace hardly diminished over the full distance.
The victor narrowly won the verdict with scoring tallies of 114-114, 115-113 and 115-112, but the two athletes were relentless and courageous, all the qualities their inspiration the legend represented.
