UK light-heavyweight Buatsi secured a victory yet disappointing debut to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's activity level likely gained him a split decision in a tight ten-round contest at the Manchester venue.
But the challenger found success, delivering effective single shots in a fight where the approaches never quite clicked, with frequent clinching marring the fight.
Two judges scored it 96-94 to Buatsi, with the final judge a 95-95 draw.
"It wasn't my greatest performance but how do champions respond? They win," Buatsi said in the ring as he was greeted with negative reactions from the audience.
The Londoner returned to winning ways after his maiden career setback - an epic battle with his previous opponent in last winter - to claim a 20th career victory.
Some ringside observers thought the challenger, 31, deserved the victory but the Derbyshire fighter suffered the second loss of his 28-fight professional journey.
The Champion Earns Victory in Dull Encounter
Buatsi's progress has plateaued in recent times through contract problems and considerable time of inactivity.
Earlier forecast as the future of UK boxing, he now finds himself trying to achieve expectations - possibly in what feels like a last chance - under new promotional backing.
He opened tentatively, with neither fighter prepared to be aggressive in a calculated initial rounds.
The challenger, 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 appearance at the higher weight class.
By the fight's midpoint, Parker had made it competitive, causing problems for the favorite, who operated with a tight guard to barely take the better stanzas.
The audience's tolerance diminished during frequent holding, with the challenger slipping to the canvas various instances during grappling.
The underdog closed well, but many rounds were hard to judge. Nevertheless, former world champion Carl Frampton - working with the broadcast network - had it strongly leaning for the challenger, scoring for Buatsi just a single round.
The victor moves on, but with the presence of hard hitter David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Homage Inspires Local Rivalry Battle
In the supporting bout, Lyndon Arthur beat Bradley Rea by close verdict in a excellent Manchester vs Manchester fight to secure the European light-heavyweight belt.
The stadium grew hushed for a deeply poignant tribute prior to the bout as ten bells tolled in honor of the city's native Hatton, who succumbed aged 46 in recently.
It was the first major televised match card in the location since the passing of Hatton. As the concluding sound ended, the stillness gave way to a chant of "there's only one Hatton".
The competition inside the ropes matched the feeling. The eventual winner was knocked down by a significant blow squarely on the face in the initial stage, rising shakily to his position on the eight count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, Rea - in rival City blue - was marked up soon, noticeable damage forming under his eye as the fighters exchanged punishing blows.
Rea, 27, delivered effective strikes but Arthur, thirty-four, fought fire with fire with stinging uppercuts as the action rarely dropped over 12 rounds.
The victor barely secured the decision with official scores of even score, narrow lead and 115-112, but both fighters were persistent and brave, exactly what their inspiration the legend stood for.
