UK light-heavyweight Buatsi made a winning yet unimpressive debut to life under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a competitive ten-round fight at the Co-op Live Arena.
But the challenger found success, landing some telling clean blows in a fight where the techniques failed to mesh, with constant grabbing spoiling the action.
The scoring judges scored it 96-94 in favor to Buatsi, with the third a 95-95 draw.
"It wasn't my best display but how do champions respond? They succeed," the victor commented in the arena as he was faced disapproval from the crowd.
The Londoner returned to winning ways after his maiden career setback - an epic battle with Callum Smith in last winter - to secure a twentieth professional win.
Various analysts believed the challenger, 31, should have been awarded the win but the contender suffered the second setback of his 28-match professional journey.
The Champion Earns Victory in Dull Match
The fighter's advancement has stalled in the past few years through contract problems and long spells of lack of fights.
Previously predicted as the future of British boxing, he now finds himself trying to fulfil that early promise - maybe in what feels like a last chance - under new promotional backing.
He started carefully, with both competitors ready to be aggressive in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in two years ago after breaking his hand during the bout, was competing in only his second fight at light heavyweight.
By the fight's midpoint, Parker had kept it close, making life awkward for Buatsi, who worked behind a tight guard to edge the cleaner stanzas.
The audience's tolerance wore thin because of frequent holding, with the challenger going down various instances during clinches.
The underdog finished the stronger, but multiple periods were hard to judge. Although, ex-champion Carl Frampton - working with Dazn - had it strongly leaning for Parker, scoring for Buatsi just only one stanza.
The victor advances, but with the presence of power puncher David Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Inspires Manchester Derby Battle
In the secondary fight, Arthur beat Bradley Rea by divided decision in a outstanding Manchester vs Manchester battle to win the European light heavyweight belt.
The stadium became quiet for a profoundly moving memorial ahead of the contest as 10 bells tolled in memory of local hero Hatton, who succumbed aged 46 in recently.
It was the initial significant broadcast match card in the location since Hatton's passing. As the last bell ended, the silence transitioned to a shout of "only one Ricky Hatton".
The action within the ring equaled the feeling. Arthur was sent to the canvas by a left hook flush on the jaw in the early round, rising shakily to his feet on the count of eight.
But the traditional red shorts of Arthur soon came forward again. On the opposite side, the opponent - in competitive blue - was marked up early, significant bruising appearing under his eye as the duo landed punishing blows.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity rarely dropped over twelve rounds.
The victor edged the result with judges scorecards of 114-114, narrow lead and wider gap, but the two athletes were persistent and brave, all the qualities their inspiration Hatton stood for.
