UK light heavyweight Buatsi secured a victory yet underwhelming beginning to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a judges' verdict in a tight 10-round fight at the Manchester venue.
But the challenger found success, landing some telling clean blows in a match where the approaches failed to mesh, with frequent clinching spoiling the contest.
The officials had it 96-94 in favor to the winner, with the remaining official a even score.
"It wasn't my greatest showing but what defines champions? They prevail," the victor stated in the ringside as he was faced disapproval from the spectators.
The British fighter returned to winning ways after his initial pro loss - an epic battle with Callum Smith in last winter - to claim a 20th pro success.
Some ringside observers felt the challenger, 31, merited the win but the contender endured the second setback of his 28-bout career.
Buatsi Secures Triumph in Slow Match
His career development has slowed in the past few years through management issues and considerable time of inactivity.
Previously predicted as the next star of the British fight scene, he now stands trying to realize his potential - maybe in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with both competitors ready to overcommit in a cagey early stages.
Parker, whose single earlier setback came at super middleweight against John Ryder in two years ago after breaking his hand mid-fight, was participating in his second fight at light heavyweight.
By the halfway stage, the underdog had kept it close, causing problems for Buatsi, who operated with a solid defense to barely take the cleaner periods.
The audience's tolerance diminished amid frequent holding, with Parker falling to the floor various instances during clinches.
Parker finished the stronger, but several stanzas were difficult to score. Nevertheless, ex-champion Carl Frampton - working with Dazn - had it strongly leaning for Parker, awarding Buatsi just a single round.
The victor advances, but with the likes of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - based on this performance - still appears challenging.
Hatton Homage Inspires Manchester Derby Fight
In the co-main event, Arthur overcame Bradley Rea by divided decision in a outstanding Manchester vs Manchester battle to secure the continental championship.
The venue grew hushed for a profoundly moving memorial ahead of the contest as a bell ceremony rang in honor of the city's native Ricky Hatton, who died at age 46 in recently.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the final chime ended, the stillness became a roar of "there's just one Hatton".
The competition during the bout matched the sentiment. The eventual winner was floored by a significant blow squarely on the face in the early round, getting up unsteadily to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon came forward again. On the opposite side, the opponent - in rival City blue - was injured early, significant bruising developing under his orbital area as the duo traded hard punches.
Rea, twenty-seven, delivered effective strikes but the champion, 34, fought fire with fire with powerful upward punches as the pace seldom decreased over twelve rounds.
The victor edged the decision with official scores of draw, narrow lead and 115-112, but both fighters were relentless and brave, everything their inspiration Hatton embodied.
