UK light-heavyweight Buatsi made a winning yet disappointing debut to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a split decision in a competitive 10-round contest at the Manchester venue.
But the challenger landed significant shots, connecting with powerful individual punches in a match where the techniques didn't complement each other, with excessive holding marring the contest.
The scoring judges had it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my greatest display but what defines champions? They prevail," Buatsi commented in the arena as he was met by disapproval from the spectators.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in February - to secure a twentieth professional win.
Several boxing experts believed the challenger, 31, merited the win but the British boxer endured the second defeat of his 28-match professional journey.
Buatsi Earns Victory in Slow Affair
His career development has slowed in recent times through contract problems and extended periods of inactivity.
Once tipped as the next star of British boxing, he now is positioned trying to achieve expectations - maybe in what appears to be a final roll of the dice - under recent support.
He started carefully, with both competitors ready to take risks in a tentative opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in two years ago after breaking his hand during the bout, was competing in only his second appearance at light heavyweight.
By the fight's midpoint, the underdog had stayed in contention, causing problems for Buatsi, who operated with a protective stance to edge the better periods.
The crowd's patience decreased because of frequent holding, with the challenger going down multiple occasions during clinches.
The underdog ended stronger, but multiple periods were difficult to score. Nevertheless, ex-champion Carl Frampton - commentating on Dazn - had it particularly wide for Parker, awarding Buatsi just a single round.
The victor progresses, but with the likes of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Hatton Memorial Inspires Local Rivalry Battle
In the supporting bout, Lyndon Arthur overcame Bradley Rea by split-decision in a excellent local rivalry battle to secure the continental title.
The stadium fell silent for a profoundly moving memorial ahead of the contest as ten bells tolled in remembrance of local hero Hatton, who succumbed 46 years old in last month.
It was the premier televised fight night in the location since the passing of Hatton. As the concluding sound faded, the silence transitioned to a chant of "only one Hatton".
The fighting within the ring equaled the feeling. The eventual winner was floored by a significant blow squarely on the jaw in the second round, standing uncertainly to his feet on the eight count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, Rea - in opposing blue - was marked up quickly, heavy swelling appearing under his orbital area as the pair traded punishing blows.
Rea, 27, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the intensity hardly diminished over 12 rounds.
The victor edged the verdict with judges scorecards of draw, close margin and clearer margin, but the two athletes were determined and full of heart, all the qualities their idol Hatton represented.
