UK light-heavyweight Buatsi secured a victory yet disappointing beginning to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a majority decision in a tight 10-round fight at the boxing arena.
But the challenger found success, connecting with powerful individual punches in a fight where the techniques didn't complement each other, with excessive holding disrupting the contest.
Two judges scored it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my greatest showing but what defines champions? They prevail," Buatsi commented in the ringside as he was met by disapproval from the audience.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with his previous opponent in February - to earn a twentieth professional win.
Various analysts felt Parker, thirty-one, deserved the win but the Derbyshire fighter suffered the second loss of his 28-bout professional journey.
The Champion Claims Win in Uneventful Match
His career development has plateaued in recent years through contract problems and considerable time of inactivity.
Earlier forecast as the next star of British boxing, he now finds himself trying to achieve expectations - maybe in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with both competitors prepared to overcommit in a tentative initial rounds.
Parker, whose single earlier setback came at super middleweight against his former opponent in two years ago after breaking his hand during the bout, was making just his second fight at light heavyweight.
By the fight's midpoint, Parker had kept it close, making life awkward for the favorite, who operated with a tight guard to barely take the better rounds.
The spectators' acceptance decreased because of frequent holding, with Parker falling to the floor several times during grappling.
The underdog closed well, but many rounds were challenging to assess. Although, former world champion the boxing analyst - providing analysis for Dazn - had it significantly in favor for the challenger, awarding Buatsi just one round.
The victor progresses, but with the presence of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the path to championship success - based on this performance - still looks steep.
Hatton Tribute Motivates All-Manchester Contest
In the secondary fight, Lyndon Arthur beat Bradley Rea by divided decision in a terrific all-Manchester contest to win the European light heavyweight title.
The venue became quiet for a profoundly moving homage prior to the bout as ten bells tolled in remembrance of Manchester's own Hatton, who died 46 years old in recently.
It was the premier televised boxing event in the location since Hatton's death. As the final chime faded, the silence gave way to a shout of "there's just one Ricky Hatton".
The action during the bout matched the sentiment. Arthur was floored by a powerful punch squarely on the face in the second round, standing uncertainly to his feet on the referee's count.
But the Manchester United-red equipment of the fighter soon advanced again. From the other corner, Rea - in opposing blue - was injured early, significant bruising appearing under his eye as the pair exchanged punishing blows.
Rea, 27, delivered effective strikes but Arthur, thirty-four, fought fire with fire with effective uppercuts as the pace hardly diminished over 12 rounds.
Arthur edged the verdict with judges scorecards of draw, close margin and 115-112, but the two athletes were persistent and courageous, exactly what their idol Hatton embodied.
