UK light-heavyweight Buatsi earned a win yet underwhelming beginning to life under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a judges' verdict in a competitive 10-round fight at the Co-op Live Arena.
But Parker found success, delivering effective single shots in a match where the styles failed to mesh, with constant grabbing marring the action.
The officials scored it 96-94 to Buatsi, with the third a 95-95 draw.
"It wasn't my greatest showing but how do champions respond? They win," the victor commented in the ringside as he was greeted with disapproval from the crowd.
The Londoner returned to winning ways after his initial pro loss - an epic battle with his previous opponent in February - to earn a 20th pro success.
Various analysts believed the challenger, thirty-one, deserved the win but the contender endured the second loss of his 28-fight career.
Buatsi Secures Triumph in Dull Encounter
His career development has slowed in recent years through promotional disputes and considerable time of lack of fights.
Once tipped as the rising talent of British boxing, he now finds himself trying to realize his potential - possibly in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with the two boxers prepared to be aggressive in a calculated initial rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand during the bout, was making just his second bout at light-heavyweight.
By the middle rounds, the underdog had kept it close, creating difficulties for the favorite, who worked behind a protective stance to edge the more effective stanzas.
The spectators' acceptance decreased amid constant clinching, with Parker going down several times during clinches.
Parker ended stronger, but multiple periods were difficult to score. However, ex-champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for Parker, giving Buatsi just a single round.
Buatsi advances, but with the likes of power puncher Benavidez, and Eastern European fighter Bivol ruling the division, the path to championship success - on this evidence - still seems difficult.
Hatton Homage Inspires Manchester Derby Fight
In the co-main event, Arthur beat Bradley Rea by close verdict in a outstanding local rivalry fight to win the continental belt.
The venue grew hushed for a deeply poignant homage before the fight as 10 bells sounded in memory of the city's native Ricky Hatton, who passed away at age 46 in recently.
It was the premier televised fight night in the location since the passing of Hatton. As the concluding sound faded, the silence gave way to a chant of "there's just one Hatton".
The fighting during the bout equaled the feeling. The eventual winner was floored by a left hook flush on the chin in the second round, standing uncertainly to his feet on the eight count.
But the red-colored equipment of Arthur soon came forward again. Across the ring, Rea - in competitive blue - was injured early, noticeable damage appearing under his orbital area as the pair traded punishing blows.
The challenger, 27, connected with strong blows but the champion, thirty-four, fought fire with fire with powerful upward punches as the pace seldom decreased over twelve rounds.
The victor narrowly won the decision with judges scorecards of even score, close margin and 115-112, but both fighters were determined and brave, all the qualities their idol Hatton embodied.
