UK light heavyweight Buatsi made a winning yet underwhelming debut to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a close 10-round bout at the Manchester venue.
But Parker found success, landing some telling single shots in a contest where the styles failed to mesh, with excessive holding marring the action.
Two judges scored it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my best performance but what defines champions? They succeed," the victor stated in the ring as he was met by boos from the audience.
The Londoner returned to winning ways after his first professional defeat - an thrilling contest with his previous opponent in last winter - to claim a twentieth professional win.
Several boxing experts felt Parker, thirty-one, should have been awarded the decision but the Derbyshire fighter suffered the second setback of his 28-fight career.
Buatsi Claims Triumph in Slow Match
Buatsi's progress has plateaued in recent times through contract problems and long spells of inactivity.
Previously predicted as the future of British boxing, he now is positioned trying to realize his potential - possibly in what feels like a ultimate opportunity - under new promotional backing.
He started carefully, with the two boxers willing to be aggressive in a calculated opening few rounds.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was making just his second appearance at light heavyweight.
By the halfway stage, Parker had made it competitive, creating difficulties for Buatsi, who worked behind a tight guard to barely take the more effective periods.
The crowd's patience wore thin because of constant clinching, with Parker going down various instances during clinches.
The underdog closed well, but multiple periods were hard to judge. Although, ex-champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for the challenger, giving Buatsi just a single round.
Buatsi advances, but with the caliber of heavy hitter Benavidez, and Russian champion Bivol leading the category, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Homage Motivates Local Rivalry Battle
In the co-main event, Arthur defeated Bradley Rea by close verdict in a excellent local rivalry fight to win the European light-heavyweight championship.
The stadium fell silent for a extremely emotional tribute before the fight as ten bells rang in memory of Manchester's own Hatton, who died at age 46 in September.
It was the first major televised fight night in the urban center since Hatton's death. As the last bell ended, the quiet became a chant of "only one Hatton".
The action inside the ropes equaled the feeling. Arthur was sent to the canvas by a significant blow flush on the chin in the initial stage, rising shakily to his feet on the count of eight.
But the red-colored shorts of the fighter soon advanced again. From the other corner, Rea - in competitive blue - was damaged quickly, noticeable damage appearing under his eye as the pair traded powerful shots.
Rea, 27, landed power punches but the champion, thirty-four, fought fire with fire with effective uppercuts as the action hardly diminished over twelve rounds.
The victor edged the verdict with judges scorecards of draw, narrow lead and 115-112, but the two athletes were relentless and full of heart, all the qualities their idol the legend embodied.
