British light-heavyweight Buatsi secured a victory yet disappointing start to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a tight 10-round fight at the boxing arena.
But Parker landed significant shots, delivering effective single shots in a contest where the approaches never quite clicked, with excessive holding spoiling the contest.
Two judges had it 96-94 in favor to Buatsi, with the final judge a 95-95 draw.
"It wasn't my best display but how do champions respond? They win," Buatsi stated in the arena as he was faced negative reactions from the audience.
The Londoner got back to winning after his initial pro loss - an epic battle with Callum Smith in February - to secure a 20th pro success.
Several boxing experts thought Parker, 31, merited the decision but the contender endured the second loss of his 28-match professional journey.
Buatsi Claims Triumph in Uneventful Encounter
Buatsi's progress has slowed in the past few years through contract problems and extended periods of inactivity.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to achieve expectations - possibly in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter willing to be aggressive in a calculated opening few rounds.
Parker, whose single earlier setback came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was making just his second appearance at light-heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for the favorite, who operated with a solid defense to narrowly win the cleaner periods.
The crowd's patience decreased amid regular grabbing, with Parker going down multiple occasions during close exchanges.
Parker finished the stronger, but many rounds were difficult to score. Although, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just one round.
The victor progresses, but with the caliber of heavy hitter David Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - on this evidence - still looks steep.
Ricky Hatton Homage Motivates All-Manchester Fight
In the co-main event, Arthur beat Rea by close verdict in a outstanding local rivalry fight to secure the European light heavyweight championship.
The stadium became quiet for a extremely emotional memorial prior to the bout as 10 bells tolled in remembrance of Manchester's own Hatton, who passed away aged 46 in September.
It was the first major televised match card in the city since the passing of Hatton. As the concluding sound ended, the stillness became a chant of "there's only one Hatton".
The fighting inside the ropes matched the feeling. The eventual winner was floored by a left hook directly to the jaw in the early round, rising shakily to his feet on the referee's count.
But the Manchester United-red shorts of Arthur soon advanced again. From the other corner, Rea - in opposing blue - was damaged quickly, noticeable damage appearing under his face as the fighters traded punishing blows.
The challenger, 27, landed power punches but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur barely secured the decision with official scores of even score, close margin and clearer margin, but each competitor were persistent and brave, everything their hero the legend stood for.
