UK light-heavyweight Buatsi made a winning yet unimpressive beginning to his career under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate likely gained him a judges' verdict in a close 10-round bout at the boxing arena.
But the challenger found success, connecting with powerful clean blows in a match where the techniques didn't complement each other, with frequent clinching disrupting the action.
Two judges had it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest showing but what defines champions? They succeed," the victor said in the arena as he was met by boos from the crowd.
The British fighter bounced back after his initial pro loss - an memorable fight with Callum Smith in February - to earn a twentieth professional win.
Some ringside observers thought Parker, 31, merited the victory but the Derbyshire fighter experienced the second defeat of his 28-fight professional journey.
The Champion Earns Triumph in Slow Match
Buatsi's progress has stalled in the past few years through promotional disputes and extended periods of inactivity.
Once tipped as the future of British boxing, he now finds himself trying to achieve expectations - possibly in what appears to be a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter willing to overcommit in a tentative opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in two years ago after suffering a hand injury during the bout, was competing in only his second fight at light heavyweight.
By the halfway stage, Parker had kept it close, creating difficulties for Buatsi, who operated with a protective stance to narrowly win the better stanzas.
The spectators' acceptance decreased because of frequent holding, with Parker going down multiple occasions during close exchanges.
The underdog ended stronger, but several stanzas were difficult to score. Although, former world champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for the challenger, giving Buatsi just only one stanza.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Hatton Tribute Fuels Local Rivalry Fight
In the supporting bout, Arthur overcame Bradley Rea by divided decision in a excellent all-Manchester battle to capture the European light heavyweight championship.
The stadium fell silent for a extremely emotional homage before the fight as a bell ceremony tolled in honor of local hero Hatton, who succumbed 46 years old in last month.
It was the premier televised boxing event in the location since Hatton's death. As the concluding sound disappeared, the stillness gave way to a roar of "there's just one Ricky Hatton".
The fighting within the ring reflected the feeling. Arthur was sent to the canvas by a left hook squarely on the jaw in the second round, standing uncertainly to his position on the count of eight.
But the Manchester United-red attire of the fighter soon pressed ahead again. On the opposite side, the opponent - in rival City blue - was marked up soon, noticeable damage forming under his eye as the pair traded powerful shots.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, responded in kind with effective uppercuts as the action hardly diminished over twelve rounds.
Arthur narrowly won the decision with scoring tallies of 114-114, narrow lead and clearer margin, but each competitor were relentless and courageous, all the qualities their hero the legend embodied.
