UK light heavyweight Buatsi made a winning yet disappointing debut to life under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a split decision in a close ten-round bout at the boxing arena.
But Parker had his moments, landing some telling individual punches in a contest where the approaches didn't complement each other, with frequent clinching disrupting the contest.
The officials had it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what defines champions? They prevail," Buatsi said in the arena as he was faced disapproval from the audience.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in February - to secure a 20th pro success.
Several boxing experts believed the challenger, thirty-one, merited the decision but the Derbyshire fighter experienced the second defeat of his 28-fight professional journey.
Buatsi Earns Win in Uneventful Encounter
Buatsi's progress has stalled in the past few years through promotional disputes and considerable time of lack of fights.
Once tipped as the rising talent of UK boxing, he now is positioned trying to achieve expectations - perhaps in what appears to be a ultimate opportunity - under recent support.
He began cautiously, with both competitors ready to be aggressive in a cagey early stages.
Parker, whose sole prior loss came at the lower weight class against John Ryder in two years ago after breaking his hand mid-fight, was competing in only his second appearance at light-heavyweight.
By the halfway stage, the underdog had kept it close, creating difficulties for the favorite, who utilized a solid defense to narrowly win the better stanzas.
The spectators' acceptance diminished during regular grabbing, with Parker going down various instances during close exchanges.
Parker ended stronger, but multiple periods were challenging to assess. However, previous titleholder the boxing analyst - providing analysis for Dazn - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
The victor advances, but with the presence of power puncher David Benavidez, and Russian champion Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Ricky Hatton Memorial Fuels Manchester Derby Contest
In the secondary fight, Arthur overcame Bradley Rea by divided decision in a excellent Manchester vs Manchester battle to capture the European light-heavyweight championship.
The venue grew hushed for a extremely emotional memorial before the fight as a bell ceremony sounded in honor of local hero Ricky Hatton, who died at age 46 in recently.
It was the premier televised boxing event in the city since Hatton's passing. As the final chime ended, the stillness transitioned to a roar of "only one Hatton".
The competition within the ring matched the feeling. The eventual winner was floored by a left hook squarely on the face in the initial stage, standing uncertainly to his footing on the referee's count.
But the Manchester United-red shorts of the fighter soon came forward again. On the opposite side, the opponent - in competitive blue - was marked up soon, significant bruising developing under his face as the fighters traded powerful shots.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with powerful upward punches as the pace hardly diminished over 12 rounds.
Arthur barely secured the verdict with official scores of 114-114, narrow lead and wider gap, but the two athletes were determined and full of heart, all the qualities their inspiration Hatton embodied.
