UK light-heavyweight Buatsi secured a victory yet unimpressive start to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a split decision in a close 10-round bout at the Manchester venue.
But the challenger had his moments, landing some telling clean blows in a match where the techniques never quite clicked, with frequent clinching spoiling the action.
Two judges judged it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my finest performance but what defines champions? They win," Buatsi commented in the ringside as he was faced negative reactions from the spectators.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with Callum Smith in last winter - to earn a twentieth professional win.
Several boxing experts felt the challenger, 31, merited the victory but the contender suffered the second setback of his 28-bout professional journey.
The Champion Claims Victory in Uneventful Affair
His career development has slowed in recent years through management issues and extended periods of inactivity.
Previously predicted as the next star of UK boxing, he now finds himself trying to fulfil that early promise - perhaps in what seems like a ultimate opportunity - under new promotional backing.
He began cautiously, with both competitors ready to be aggressive in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after breaking his hand in the contest, was participating in his second fight at light heavyweight.
By the fight's midpoint, the underdog had kept it close, causing problems for the favorite, who utilized a solid defense to barely take the cleaner rounds.
The spectators' acceptance wore thin because of regular grabbing, with the challenger going down several times during close exchanges.
The underdog finished the stronger, but many rounds were difficult to score. However, former world champion Carl Frampton - commentating on the broadcast network - had it significantly in favor for Parker, awarding Buatsi just one round.
Buatsi progresses, but with the likes of hard hitter David Benavidez, and Eastern European fighter Bivol ruling the division, the road to world glory - on this evidence - still appears challenging.
Hatton Tribute Inspires Manchester Derby Fight
In the supporting bout, Lyndon Arthur defeated Rea by split-decision in a excellent all-Manchester contest to win the European light-heavyweight championship.
The arena grew hushed for a deeply poignant tribute ahead of the contest as a bell ceremony sounded in memory of local hero Hatton, who succumbed aged 46 in last month.
It was the premier televised match card in the location since the passing of Hatton. As the final chime ended, the quiet became a chant of "only one Ricky Hatton".
The competition during the bout reflected the feeling. The eventual winner was sent to the canvas by a powerful punch squarely on the chin in the early round, standing uncertainly to his feet on the count of eight.
But the Manchester United-red equipment of the fighter soon pressed ahead again. Across the ring, Rea - in opposing blue - was marked up quickly, heavy swelling appearing under his eye as the duo exchanged hard punches.
Rea, 27, connected with strong blows but Arthur, thirty-four, matched the intensity with effective uppercuts as the action seldom decreased over twelve rounds.
The victor edged the result with judges scorecards of 114-114, narrow lead and wider gap, but each competitor were determined and brave, exactly what their idol Hatton represented.
