British light-heavyweight Buatsi earned a win yet disappointing start to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a judges' verdict in a competitive 10-round bout at the Manchester venue.
But Parker had his moments, connecting with powerful clean blows in a fight where the techniques didn't complement each other, with excessive holding disrupting the contest.
The officials judged it 96-94 in favor to Buatsi, with the third a 95-95 draw.
"It wasn't my best showing but what do champions do? They prevail," the victor stated in the ring as he was greeted with negative reactions from the spectators.
The Londoner got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to secure a twentieth professional win.
Some ringside observers thought Parker, thirty-one, should have been awarded the decision but the contender experienced the second loss of his 28-fight career.
The Champion Secures Triumph in Dull Match
Buatsi's progress has plateaued in the past few years through management issues and extended periods of inactivity.
Previously predicted as the next star of British boxing, he now is positioned trying to achieve expectations - possibly in what appears to be a ultimate opportunity - under new promotional backing.
He started carefully, with the two boxers willing to take risks in a calculated initial rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand during the bout, was making just his second appearance at light heavyweight.
By the fight's midpoint, Parker had made it competitive, making life awkward for the favorite, who utilized a tight guard to narrowly win the more effective periods.
The audience's tolerance decreased amid frequent holding, with Parker slipping to the canvas various instances during grappling.
Parker closed well, but multiple periods were hard to judge. Nevertheless, ex-champion Carl Frampton - commentating on Dazn - had it significantly in favor for the challenger, awarding Buatsi just one round.
Buatsi moves on, but with the likes of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still appears challenging.
Hatton Memorial Fuels Manchester Derby Battle
In the co-main event, Lyndon Arthur overcame Bradley Rea by divided decision in a outstanding Manchester vs Manchester contest to win the European light-heavyweight title.
The stadium grew hushed for a extremely emotional tribute before the fight as ten bells tolled in honor of the city's native Ricky Hatton, who succumbed 46 years old in recently.
It was the initial significant broadcast fight night in the urban center since the passing of Hatton. As the last bell ended, the silence transitioned to a chant of "there's just one Hatton".
The fighting within the ring matched the feeling. Arthur was floored by a left hook flush on the jaw in the initial stage, rising shakily to his position on the count of eight.
But the red-colored equipment of Arthur soon pressed ahead again. On the opposite side, Rea - in competitive blue - was injured soon, significant bruising appearing under his face as the duo exchanged powerful shots.
The challenger, 27, connected with strong blows but the champion, 34, responded in kind with powerful upward punches as the action seldom decreased over the full distance.
Arthur barely secured the result with scoring tallies of even score, narrow lead and wider gap, but both fighters were relentless and brave, everything their idol the legend embodied.
