British light heavyweight Buatsi secured a victory yet underwhelming beginning to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a majority decision in a close 10-round fight at the Co-op Live Arena.
But the challenger landed significant shots, landing some telling clean blows in a contest where the approaches didn't complement each other, with constant grabbing disrupting the contest.
The scoring judges had it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my finest showing but what do champions do? They succeed," Buatsi commented in the ring as he was greeted with disapproval from the audience.
The Londoner bounced back after his first professional defeat - an epic battle with Callum Smith in last winter - to secure a twentieth professional win.
Various analysts thought the challenger, thirty-one, merited the victory but the Derbyshire fighter endured the second defeat of his 28-fight professional journey.
Buatsi Earns Victory in Slow Match
His career development has stalled in recent times through contract problems and extended periods of lack of fights.
Previously predicted as the future of British boxing, he now stands trying to realize his potential - maybe in what feels like a ultimate opportunity - under recent support.
He opened tentatively, with neither fighter willing to be aggressive in a tentative initial rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in two years ago after damaging his hand during the bout, was making just his second appearance at light-heavyweight.
By the middle rounds, Parker had made it competitive, making life awkward for Buatsi, who operated with a tight guard to edge the better stanzas.
The spectators' acceptance decreased because of constant clinching, with the challenger going down several times during close exchanges.
The underdog finished the stronger, but many rounds were difficult to score. Although, ex-champion the boxing analyst - working with Dazn - had it strongly leaning for the challenger, awarding Buatsi just one round.
Buatsi progresses, but with the presence of heavy hitter Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the road to world glory - on this evidence - still seems difficult.
Ricky Hatton Tribute Inspires Local Rivalry Battle
In the supporting bout, Arthur beat Bradley Rea by divided decision in a excellent all-Manchester battle to capture the continental title.
The arena grew hushed for a extremely emotional memorial prior to the bout as 10 bells sounded in remembrance of local hero Hatton, who succumbed at age 46 in last month.
It was the initial significant broadcast boxing event in the urban center since the passing of Hatton. As the last bell disappeared, the quiet became a shout of "there's only one Ricky Hatton".
The action within the ring reflected the emotion. Arthur was floored by a significant blow flush on the chin in the early round, rising shakily to his footing on the count of eight.
But the red-colored equipment of Arthur soon pressed ahead again. On the opposite side, Rea - in competitive blue - was injured soon, noticeable damage developing under his face as the fighters landed hard punches.
Rea, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity seldom decreased over the full distance.
The victor edged the result with judges scorecards of even score, 115-113 and clearer margin, but both fighters were relentless and full of heart, all the qualities their hero the legend embodied.
