British light heavyweight Buatsi made a winning yet disappointing debut to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a majority decision in a competitive 10-round contest at the Co-op Live Arena.
But Parker had his moments, delivering effective clean blows in a fight where the techniques failed to mesh, with constant grabbing disrupting the fight.
The officials had it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest performance but how do champions respond? They succeed," the victor commented in the ring as he was greeted with boos from the spectators.
The Londoner returned to winning ways after his first professional defeat - an thrilling contest with his previous opponent in last winter - to secure a 20th pro success.
Various analysts thought Parker, thirty-one, deserved the decision but the British boxer experienced the second defeat of his 28-bout professional journey.
Buatsi Secures Win in Slow Encounter
His career development has plateaued in the past few years through contract problems and considerable time of lack of fights.
Earlier forecast as the future of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a last chance - under recent support.
He opened tentatively, with the two boxers ready to take risks in a calculated opening few rounds.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in 2022 after damaging his hand mid-fight, was competing in only his second appearance at light heavyweight.
By the fight's midpoint, the underdog had made it competitive, making life awkward for the favorite, who utilized a protective stance to narrowly win the cleaner stanzas.
The audience's tolerance wore thin because of frequent holding, with the challenger slipping to the canvas several times during clinches.
The underdog closed well, but several stanzas were challenging to assess. Nevertheless, former world champion Carl Frampton - working with Dazn - had it particularly wide for the challenger, giving Buatsi just one round.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Russian champion Bivol leading the category, the road to world glory - on this evidence - still seems difficult.
Ricky Hatton Homage Fuels Local Rivalry Contest
In the secondary fight, Arthur defeated Rea by split-decision in a excellent all-Manchester fight to capture the European light-heavyweight championship.
The stadium fell silent for a deeply poignant memorial before the fight as a bell ceremony tolled in memory of Manchester's own Ricky Hatton, who died at age 46 in September.
It was the first major televised boxing event in the city since the passing of Hatton. As the final chime faded, the quiet transitioned to a shout of "only one Hatton".
The fighting inside the ropes matched the sentiment. Arthur was knocked down by a powerful punch squarely on the chin in the initial stage, standing uncertainly to his footing on the eight count.
But the traditional red attire of the fighter soon advanced again. On the opposite side, the opponent - in opposing blue - was damaged soon, noticeable damage forming under his eye as the pair exchanged punishing blows.
Rea, 27, landed power punches but the champion, 34, fought fire with fire with powerful upward punches as the intensity seldom decreased over the full distance.
The victor narrowly won the result with judges scorecards of 114-114, 115-113 and wider gap, but the two athletes were determined and brave, exactly what their inspiration the legend represented.
