UK light-heavyweight Buatsi earned a win yet underwhelming 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 appeared to earn him a majority decision in a close ten-round fight at the Co-op Live Arena.
But Parker landed significant shots, connecting with powerful individual punches in a match where the styles didn't complement each other, with excessive holding spoiling the contest.
Two judges scored it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my finest display but how do champions respond? They succeed," the victor said in the ring as he was faced negative reactions from the spectators.
The Londoner bounced back after his initial pro loss - an thrilling contest with Callum Smith in last winter - to claim a twentieth professional win.
Several boxing experts felt Parker, thirty-one, deserved the decision but the British boxer experienced the second defeat of his 28-fight career.
Buatsi Earns Win in Dull Match
Buatsi's progress has slowed in recent years through management issues and extended periods of inactivity.
Once tipped as the future of British boxing, he now is positioned trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under recent support.
He began cautiously, with neither fighter ready to overcommit in a calculated early stages.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after damaging his hand during the bout, was competing in only his second fight at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for Buatsi, who utilized a protective stance to barely take the better periods.
The audience's tolerance decreased amid frequent holding, with the challenger slipping to the canvas several times during close exchanges.
Parker finished the stronger, but several stanzas were challenging to assess. However, former world champion Carl Frampton - commentating on Dazn - had it particularly wide for the challenger, awarding Buatsi just a single round.
The victor moves on, but with the caliber of heavy hitter David Benavidez, and Eastern European fighter Bivol leading the category, the road to world glory - based on this performance - still appears challenging.
Hatton Tribute Motivates Local Rivalry Battle
In the supporting bout, Lyndon Arthur defeated Rea by close verdict in a terrific all-Manchester fight to capture the European light heavyweight championship.
The stadium grew hushed for a extremely emotional homage ahead of the contest as ten bells rang in remembrance of local hero Hatton, who succumbed at age 46 in last month.
It was the premier televised fight night in the location since Hatton's passing. As the final chime disappeared, the quiet gave way to a shout of "there's only one Ricky Hatton".
The competition inside the ropes equaled the sentiment. Arthur was floored by a significant blow flush on the chin in the second round, standing uncertainly to his footing on the referee's count.
But the red-colored shorts of the fighter soon pressed ahead again. From the other corner, Rea - in competitive blue - was marked up quickly, significant bruising appearing under his orbital area as the duo exchanged powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with powerful upward punches as the intensity seldom decreased over 12 rounds.
Arthur edged the decision with judges scorecards of even score, 115-113 and clearer margin, but both fighters were persistent and brave, exactly what their hero the legend stood for.
