British light-heavyweight Buatsi made a winning yet disappointing start to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a split decision in a competitive 10-round fight at the Manchester venue.
But the challenger landed significant shots, connecting with powerful clean blows in a match where the techniques never quite clicked, with excessive holding marring the contest.
The scoring judges judged it 96-94 to the winner, with the final judge a 95-95.
"It wasn't my best performance but how do champions respond? They succeed," Buatsi stated in the ringside as he was faced boos from the spectators.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a 20th career victory.
Several boxing experts felt Parker, thirty-one, should have been awarded the victory but the British boxer experienced the second loss of his 28-bout career.
Buatsi Claims Triumph in Uneventful Affair
The fighter's advancement has plateaued in the past few years through promotional disputes and extended periods of lack of fights.
Once tipped as the future of UK boxing, he now stands trying to fulfil that early promise - maybe in what seems like a final roll of the dice - under new promotional backing.
He started carefully, with both competitors ready to overcommit in a tentative initial rounds.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after breaking his hand during the bout, was competing in only his second appearance at light-heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who operated with a tight guard to edge the better stanzas.
The spectators' acceptance diminished during regular grabbing, with Parker slipping to the canvas various instances during grappling.
Parker ended stronger, but many rounds were challenging to assess. Nevertheless, former world champion Carl Frampton - working with Dazn - had it significantly in favor for the challenger, awarding Buatsi just a single round.
Buatsi moves on, but with the likes of power puncher David Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still appears challenging.
Hatton Homage Inspires Local Rivalry Fight
In the supporting bout, Lyndon Arthur defeated Bradley Rea by split-decision in a outstanding local rivalry contest to capture the continental championship.
The arena became quiet for a extremely emotional memorial ahead of the contest as ten bells tolled in memory of local hero Ricky Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast boxing event in the location since Hatton's death. As the last bell faded, the silence gave way to a chant of "there's only one Hatton".
The action within the ring reflected the emotion. The eventual winner was knocked down by a significant blow flush on the face in the initial stage, rising shakily to his position on the count of eight.
But the red-colored attire of Arthur soon advanced again. Across the ring, the opponent - in rival City blue - was damaged early, noticeable damage appearing under his eye as the fighters traded powerful shots.
The challenger, 27, landed power punches but the champion, 34, fought fire with fire with powerful upward punches as the action seldom decreased over the full distance.
The victor narrowly won the result with official scores of 114-114, narrow lead and wider gap, but each competitor were persistent and brave, all the qualities their inspiration Hatton stood for.
