British light-heavyweight Buatsi secured a victory yet underwhelming beginning to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a tight 10-round bout at the boxing arena.
But Parker found success, connecting with powerful clean blows in a contest where the styles didn't complement each other, with excessive holding marring the action.
Two judges scored it 96-94 in favor to the winner, with the final judge a 95-95.
"It wasn't my best performance but how do champions respond? They prevail," the victor stated in the ringside as he was greeted with boos from the crowd.
The British fighter bounced back after his maiden career setback - an epic battle with Callum Smith in February - to secure a 20th career victory.
Some ringside observers believed the challenger, thirty-one, should have been awarded the victory but the Derbyshire fighter suffered the second defeat of his 28-match career.
Buatsi Secures Win in Slow Match
Buatsi's progress has plateaued in recent times through management issues and long spells of lack of fights.
Once tipped as the future of UK boxing, he now stands trying to fulfil that early promise - possibly in what seems like a last chance - under new promotional backing.
He opened tentatively, with both competitors willing to take risks in a cagey initial rounds.
Parker, whose sole prior loss came at super middleweight against his former opponent in two years ago after breaking his hand during the bout, was participating in his second fight at light-heavyweight.
By the middle rounds, Parker had kept it close, causing problems for the favorite, who operated with a solid defense to barely take the cleaner periods.
The crowd's patience diminished during regular grabbing, with Parker falling to the floor various instances during close exchanges.
The underdog ended stronger, but several stanzas were challenging to assess. However, ex-champion the boxing analyst - working with the broadcast network - had it strongly leaning for Parker, giving Buatsi just one round.
The victor advances, but with the presence of hard hitter Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Memorial Inspires All-Manchester Battle
In the co-main event, Arthur beat Bradley Rea by close verdict in a outstanding Manchester vs Manchester contest to secure the continental championship.
The venue grew hushed for a profoundly moving tribute ahead of the contest as a bell ceremony rang in memory of local hero Hatton, who succumbed 46 years old in recently.
It was the first major televised match card in the location since Hatton's death. As the last bell faded, the silence gave way to a roar of "there's just one Ricky Hatton".
The competition during the bout matched the feeling. The eventual winner was knocked down by a left hook flush on the chin in the early round, standing uncertainly to his position on the referee's count.
But the Manchester United-red equipment of Arthur soon came forward again. From the other corner, the opponent - in opposing blue - was injured soon, noticeable damage forming under his face as the pair traded powerful shots.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with effective uppercuts as the action rarely dropped over the full distance.
Arthur barely secured the verdict with judges scorecards of even score, close margin and clearer margin, but the two athletes were persistent and full of heart, exactly what their hero Hatton embodied.
