UK light heavyweight Buatsi made a winning yet disappointing beginning to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a close ten-round fight at the Co-op Live Arena.
But the challenger had his moments, connecting with powerful clean blows in a match where the styles failed to mesh, with constant grabbing spoiling the action.
The scoring judges judged it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my finest display but how do champions respond? They win," Buatsi stated in the ring as he was faced disapproval from the crowd.
The British fighter bounced back after his first professional defeat - an memorable fight with Callum Smith in last winter - to earn a 20th career victory.
Various analysts thought Parker, thirty-one, merited the victory but the contender suffered the second setback of his 28-bout career.
The Champion Claims Triumph in Uneventful Encounter
The fighter's advancement has stalled in recent years through management issues and considerable time of lack of fights.
Earlier forecast as the rising talent of UK boxing, he now finds himself trying to achieve expectations - possibly in what seems like a final roll of the dice - under recent support.
He began cautiously, with neither fighter willing to be aggressive in a calculated early stages.
Parker, whose only previous defeat came at super middleweight against John Ryder in 2022 after suffering a hand injury in the contest, was making just his second appearance at light-heavyweight.
By the halfway stage, the underdog had kept it close, creating difficulties for the favorite, who worked behind a tight guard to edge the better stanzas.
The audience's tolerance diminished amid frequent holding, with Parker going down various instances during grappling.
Parker finished the stronger, but many rounds were hard to judge. However, previous titleholder Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, giving Buatsi just a single round.
The victor moves on, but with the presence of power puncher David Benavidez, and Eastern European fighter Bivol leading the category, the journey to titles - judging by this showing - still appears challenging.
Ricky Hatton Tribute Motivates All-Manchester Fight
In the co-main event, Lyndon Arthur beat Bradley Rea by split-decision in a excellent Manchester vs Manchester fight to capture the European light-heavyweight belt.
The venue grew hushed for a profoundly moving tribute ahead of the contest as 10 bells tolled in honor of Manchester's own Hatton, who succumbed 46 years old in recently.
It was the first major televised match card in the city since Hatton's passing. As the concluding sound disappeared, the quiet gave way to a chant of "only one Ricky Hatton".
The action during the bout matched the emotion. The eventual winner was floored by a left hook directly to the face in the early round, standing uncertainly to his feet on the count of eight.
But the Manchester United-red attire of the fighter soon pressed ahead again. Across the ring, Rea - in opposing blue - was marked up quickly, heavy swelling developing under his eye as the fighters exchanged powerful shots.
Rea, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with effective uppercuts as the intensity seldom decreased over 12 rounds.
Arthur edged the verdict with scoring tallies of 114-114, close margin and clearer margin, but both fighters were relentless and brave, everything their inspiration the legend represented.
