British light-heavyweight Buatsi earned a win yet underwhelming debut to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a close 10-round contest at the Manchester venue.
But the challenger had his moments, connecting with powerful single shots in a match where the approaches failed to mesh, with frequent clinching marring the action.
The scoring judges judged it 96-94 in favor to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest showing but what defines champions? They win," Buatsi said in the ringside as he was faced negative reactions from the spectators.
The Londoner got back to winning after his maiden career setback - an thrilling contest with Callum Smith in February - to claim a 20th career victory.
Some ringside observers believed Parker, 31, merited the victory but the contender suffered the second defeat of his 28-bout professional journey.
Buatsi Claims Triumph in Uneventful Match
Buatsi's progress has plateaued in the past few years through contract problems and considerable time of inactivity.
Earlier forecast as the next star of UK boxing, he now finds himself trying to achieve expectations - possibly in what feels like a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter willing to overcommit in a tentative opening few rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after suffering a hand injury during the bout, was making just his second bout at light-heavyweight.
By the middle rounds, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a tight guard to narrowly win the more effective periods.
The spectators' acceptance decreased because of frequent holding, with the challenger slipping to the canvas various instances during close exchanges.
The underdog ended stronger, but several stanzas were hard to judge. However, ex-champion Carl Frampton - working with the broadcast network - had it particularly wide for Parker, awarding Buatsi just a single round.
Buatsi progresses, but with the likes of power puncher Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Memorial Inspires Manchester Derby Contest
In the co-main event, Lyndon Arthur beat Rea by divided decision in a terrific all-Manchester fight to capture the European light heavyweight title.
The arena fell silent for a deeply poignant memorial ahead of the contest as a bell ceremony sounded in remembrance of local hero Ricky Hatton, who died aged 46 in recently.
It was the initial significant broadcast boxing event in the urban center since Hatton's death. As the last bell ended, the quiet transitioned to a chant of "only one Ricky Hatton".
The action within the ring equaled the emotion. Arthur was knocked down by a powerful punch directly to the chin in the initial stage, getting up unsteadily to his position on the eight count.
But the red-colored shorts of Arthur soon came forward again. From the other corner, Rea - in opposing blue - was marked up early, heavy swelling appearing under his eye as the duo exchanged hard punches.
Rea, twenty-seven, landed power punches but the champion, thirty-four, matched the intensity with powerful upward punches as the intensity rarely dropped over twelve rounds.
Arthur barely secured the verdict with scoring tallies of 114-114, narrow lead and wider gap, but the two athletes were determined and courageous, all the qualities their inspiration the legend stood for.
