UK light heavyweight Buatsi secured a victory yet unimpressive start to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a split decision in a close 10-round bout at the boxing arena.
But the challenger had his moments, landing some telling individual punches in a fight where the approaches failed to mesh, with constant grabbing marring the fight.
Two judges scored it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest performance but what do champions do? They succeed," Buatsi stated in the ring as he was faced negative reactions from the crowd.
The Londoner returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a 20th pro success.
Several boxing experts believed the challenger, thirty-one, deserved the win but the contender suffered the second loss of his 28-fight professional journey.
Buatsi Secures Win in Dull Match
The fighter's advancement has plateaued in the past few years through contract problems and long spells of lack of fights.
Previously predicted as the next star of the British fight scene, he now stands trying to realize his potential - perhaps in what feels like a final roll of the dice - under new promotional backing.
He began cautiously, with neither fighter prepared to take risks in a calculated opening few rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in two years ago after suffering a hand injury mid-fight, was making just his second fight at the higher weight class.
By the fight's midpoint, Parker had kept it close, making life awkward for the favorite, who worked behind a protective stance to narrowly win the better periods.
The audience's tolerance decreased amid constant clinching, with the challenger slipping to the canvas various instances during clinches.
The underdog ended stronger, but several stanzas were difficult to score. Although, former world champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just only one stanza.
The victor advances, but with the likes of power puncher David Benavidez, and Eastern European fighter Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Tribute Inspires Local Rivalry Contest
In the supporting bout, Arthur beat Rea by divided decision in a outstanding Manchester vs Manchester contest to win the continental championship.
The stadium became quiet for a profoundly moving tribute prior to the bout as 10 bells rang in honor of Manchester's own Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast boxing event in the city since Hatton's passing. As the final chime faded, the silence transitioned to a chant of "only one Ricky Hatton".
The fighting during the bout reflected the emotion. The eventual winner was knocked down by a significant blow flush on the face in the early round, getting up unsteadily to his feet on the referee's count.
But the traditional red equipment of the fighter soon pressed ahead again. On the opposite side, the opponent - in opposing blue - was marked up quickly, noticeable damage appearing under his face as the duo exchanged punishing blows.
Rea, 27, delivered effective strikes but Arthur, thirty-four, fought fire with fire with effective uppercuts as the action rarely dropped over 12 rounds.
Arthur narrowly won the result with official scores of even score, narrow lead and wider gap, but each competitor were determined and courageous, all the qualities their idol the legend embodied.
