British light heavyweight Buatsi made a winning 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 likely gained him a split decision in a tight 10-round bout at the Manchester venue.
But Parker had his moments, delivering effective individual punches in a contest where the styles never quite clicked, with frequent clinching disrupting the contest.
The scoring judges had it 96-94 for to the winner, with the remaining official a even score.
"It wasn't my greatest performance but what do champions do? They succeed," the victor commented in the ring as he was greeted with disapproval from the audience.
The British fighter returned to winning ways after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a 20th career victory.
Some ringside observers believed the challenger, 31, merited the win but the British boxer suffered the second defeat of his 28-fight career.
Buatsi Earns Win in Slow Affair
The fighter's advancement has slowed in recent years through contract problems and extended periods of lack of fights.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to achieve expectations - maybe in what seems like a last chance - under fresh management.
He started carefully, with both competitors ready to take risks in a tentative opening few rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was competing in only his second bout at light heavyweight.
By the halfway stage, the underdog had kept it close, causing problems for the favorite, who utilized a protective stance to barely take the better rounds.
The crowd's patience decreased during regular grabbing, with Parker slipping to the canvas various instances during close exchanges.
The underdog ended stronger, but multiple periods were difficult to score. However, ex-champion the boxing analyst - providing analysis for Dazn - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor moves on, but with the presence of heavy hitter David Benavidez, and Russian champion Bivol ruling the division, the road to world glory - based on this performance - still looks steep.
Hatton Homage Motivates Manchester Derby Contest
In the co-main event, Arthur defeated Rea by split-decision in a terrific Manchester vs Manchester fight to capture the European light heavyweight championship.
The arena grew hushed for a deeply poignant tribute prior to the bout as 10 bells rang in honor of local hero Ricky Hatton, who died aged 46 in September.
It was the premier televised fight night in the location since the passing of Hatton. As the concluding sound ended, the stillness became a roar of "there's just one Hatton".
The action inside the ropes reflected the emotion. Arthur was sent to the canvas by a significant blow flush on the jaw in the early round, standing uncertainly to his footing on the eight count.
But the red-colored shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in competitive blue - was damaged soon, heavy swelling appearing under his eye as the pair traded hard punches.
Rea, 27, delivered effective strikes but Arthur, 34, fought fire with fire with stinging uppercuts as the action hardly diminished over 12 rounds.
The victor edged the decision with judges scorecards of draw, narrow lead and clearer margin, but each competitor were relentless and full of heart, exactly what their hero Hatton represented.
