British light-heavyweight Buatsi earned a win yet unimpressive debut to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a close 10-round fight at the boxing arena.
But the challenger had his moments, landing some telling single shots in a match where the techniques failed to mesh, with constant grabbing marring the action.
The scoring judges had it 96-94 for to the winner, with the third a even score.
"It wasn't my greatest display but what do champions do? They win," the victor commented in the ringside as he was faced disapproval from the crowd.
The British fighter returned to winning ways after his initial pro loss - an memorable fight with his previous opponent in last winter - to secure a 20th career victory.
Several boxing experts felt the challenger, 31, should have been awarded the victory but the contender suffered the second setback of his 28-fight professional journey.
Buatsi Claims Win in Dull Match
His career development has stalled in recent years through promotional disputes and long spells of inactivity.
Previously predicted as the future of British boxing, he now finds himself trying to realize his potential - maybe in what seems like a final roll of the dice - under fresh management.
He started carefully, with both competitors prepared to overcommit in a calculated initial rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in two years ago after damaging his hand during the bout, was participating in his second fight at light heavyweight.
By the middle rounds, the underdog had made it competitive, making life awkward for Buatsi, who operated with a tight guard to edge the cleaner periods.
The crowd's patience wore thin because of regular grabbing, with Parker falling to the floor several times during grappling.
The underdog finished the stronger, but several stanzas were hard to judge. However, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor advances, but with the presence of heavy hitter David Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - on this evidence - still looks steep.
Ricky Hatton Memorial Inspires Manchester Derby Battle
In the supporting bout, Lyndon Arthur beat Bradley Rea by divided decision in a outstanding local rivalry fight to win the European light-heavyweight title.
The arena fell silent for a extremely emotional memorial prior to the bout as a bell ceremony sounded in remembrance of the city's native Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast match card in the location since Hatton's passing. As the last bell faded, the silence gave way to a roar of "there's just one Hatton".
The competition within the ring equaled the feeling. Arthur was knocked down by a left hook directly to the face in the second round, rising shakily to his footing on the referee's count.
But the traditional red equipment of Arthur soon advanced again. Across the ring, Rea - in competitive blue - was damaged early, heavy swelling appearing under his orbital area as the pair exchanged hard punches.
Rea, 27, connected with strong blows but the champion, thirty-four, fought fire with fire with effective uppercuts as the pace rarely dropped over twelve rounds.
Arthur edged the decision with scoring tallies of even score, 115-113 and 115-112, but both fighters were persistent and full of heart, all the qualities their inspiration Hatton stood for.
