British light-heavyweight Buatsi secured a victory yet underwhelming debut to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a majority decision in a tight 10-round bout at the Co-op Live Arena.
But the challenger had his moments, delivering effective individual punches in a fight where the styles failed to mesh, with frequent clinching marring the fight.
The scoring judges scored it 96-94 for to Buatsi, with the third a even score.
"It wasn't my finest performance but what defines champions? They prevail," Buatsi stated in the ringside as he was met by boos from the spectators.
The Londoner got back to winning after his first professional defeat - an epic battle with his previous opponent in February - to earn a 20th career victory.
Several boxing experts thought the challenger, thirty-one, should have been awarded the decision but the contender experienced the second loss of his 28-match professional journey.
The Champion Earns Triumph in Uneventful Encounter
Buatsi's progress has stalled in the past few years through contract problems and considerable time of inactivity.
Earlier forecast as the future of the British fight scene, he now is positioned trying to fulfil that early promise - perhaps in what feels like a final roll of the dice - under new promotional backing.
He opened tentatively, with both competitors prepared to be aggressive in a tentative initial rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in two years ago after suffering a hand injury in the contest, was participating in his second bout at the higher weight class.
By the halfway stage, Parker had stayed in contention, making life awkward for the favorite, who utilized a solid defense to narrowly win the better periods.
The audience's tolerance diminished because of frequent holding, with the challenger falling to the floor several times during close exchanges.
Parker ended stronger, but multiple periods were difficult to score. Nevertheless, former world champion Carl Frampton - working with Dazn - had it strongly leaning for the challenger, scoring for Buatsi just a single round.
The victor advances, but with the caliber of heavy hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - on this evidence - still looks steep.
Hatton Homage Fuels Manchester Derby Battle
In the secondary fight, Lyndon Arthur beat Bradley Rea by split-decision in a terrific local rivalry battle to capture the European light heavyweight championship.
The stadium fell silent for a extremely emotional tribute before the fight as a bell ceremony rang in memory of the city's native Ricky Hatton, who died 46 years old in last month.
It was the first major televised match card in the location since Hatton's death. As the concluding sound disappeared, the stillness became a roar of "there's just one Hatton".
The competition during the bout equaled the emotion. The eventual winner was knocked down by a significant blow squarely on the face in the early round, standing uncertainly to his position on the eight count.
But the Manchester United-red equipment of Arthur soon advanced again. On the opposite side, Rea - in opposing blue - was injured early, heavy swelling developing under his eye as the fighters traded punishing blows.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, fought fire with fire with effective uppercuts as the action seldom decreased over twelve rounds.
Arthur barely secured the decision with official scores of draw, narrow lead and clearer margin, but the two athletes were relentless and brave, exactly what their hero the legend embodied.
