UK light heavyweight Buatsi made a winning yet underwhelming start to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a majority decision in a tight 10-round contest at the Manchester venue.
But the challenger landed significant shots, connecting with powerful clean blows in a contest where the approaches didn't complement each other, with frequent clinching disrupting the contest.
The officials scored it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest performance but what do champions do? They win," the victor said in the arena as he was faced negative reactions from the spectators.
The British fighter got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to earn a 20th pro success.
Various analysts felt Parker, thirty-one, merited the decision but the Derbyshire fighter suffered the second loss of his 28-match professional journey.
Buatsi Claims Win in Uneventful Affair
His career development has stalled in recent times through contract problems and extended periods of inactivity.
Once tipped as the future of UK boxing, he now stands trying to realize his potential - maybe in what feels like a last chance - under recent support.
He began cautiously, with neither fighter ready to take risks in a calculated early stages.
Parker, whose sole prior loss came at super middleweight against his former opponent in 2022 after suffering a hand injury during the bout, was competing in only his second appearance at light heavyweight.
By the middle rounds, Parker had stayed in contention, causing problems for Buatsi, who worked behind a protective stance to narrowly win the more effective rounds.
The spectators' acceptance wore thin amid frequent holding, with the challenger going down multiple occasions during close exchanges.
Parker ended stronger, but many rounds were challenging to assess. Although, former world champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just one round.
Buatsi advances, but with the likes of hard hitter Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - based on this performance - still looks steep.
Ricky Hatton Homage Inspires All-Manchester Contest
In the supporting bout, Arthur defeated Bradley Rea by close verdict in a terrific local rivalry fight to capture the European light heavyweight belt.
The arena grew hushed for a extremely emotional tribute prior to the bout as 10 bells tolled in honor of local hero Hatton, who died aged 46 in September.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the last bell ended, the quiet became a shout of "there's only one Ricky Hatton".
The action within the ring equaled the feeling. The eventual winner was sent to the canvas by a left hook directly to the jaw in the second round, rising shakily to his footing on the eight count.
But the traditional red shorts of Arthur soon pressed ahead again. On the opposite side, Rea - in rival City blue - was injured early, noticeable damage appearing under his eye as the fighters traded powerful shots.
Rea, 27, connected with strong blows but the champion, thirty-four, fought fire with fire with powerful upward punches as the action seldom decreased over 12 rounds.
Arthur edged the decision with scoring tallies of 114-114, 115-113 and wider gap, but the two athletes were relentless and courageous, all the qualities their idol the legend embodied.
