UK light-heavyweight Buatsi made a winning yet disappointing start to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a judges' verdict in a tight ten-round fight at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful single shots in a fight where the approaches failed to mesh, with excessive holding disrupting the contest.
Two judges judged it 96-94 to the winner, with the third a even score.
"It wasn't my finest display but what defines champions? They win," the victor stated in the arena as he was greeted with disapproval from the spectators.
The British fighter returned to winning ways after his maiden career setback - an thrilling contest with Callum Smith in February - to earn a twentieth professional win.
Several boxing experts believed Parker, thirty-one, deserved the victory but the British boxer endured the second loss of his 28-fight professional journey.
Buatsi Secures Victory in Slow Encounter
His career development has slowed in recent times through contract problems and extended periods of inactivity.
Earlier forecast as the future of British boxing, he now is positioned trying to achieve expectations - possibly in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with the two boxers ready to take risks in a cagey initial rounds.
The challenger, whose only previous defeat came at the lower weight class against his former opponent in 2022 after breaking his hand during the bout, was making just his second bout at light-heavyweight.
By the middle rounds, Parker had kept it close, creating difficulties for Buatsi, who utilized a protective stance to narrowly win the better stanzas.
The spectators' acceptance wore thin because of frequent holding, with Parker falling to the floor multiple occasions during clinches.
The underdog finished the stronger, but several stanzas were difficult to score. Nevertheless, former world champion the boxing analyst - commentating on Dazn - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
Buatsi moves on, but with the caliber of hard hitter Benavidez, and Russian champion Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Homage Inspires All-Manchester Contest
In the secondary fight, Arthur overcame Rea by split-decision in a outstanding Manchester vs Manchester contest to secure the European light-heavyweight championship.
The arena grew hushed for a profoundly moving homage ahead of the contest as 10 bells sounded in memory of local hero Ricky Hatton, who died 46 years old in recently.
It was the initial significant broadcast boxing event in the location since Hatton's passing. As the final chime faded, the stillness became a roar of "there's only one Hatton".
The fighting during the bout equaled the sentiment. The eventual winner was knocked down by a powerful punch directly to the chin in the initial stage, rising shakily to his footing on the eight count.
But the traditional red shorts of the fighter soon advanced again. On the opposite side, the opponent - in competitive blue - was damaged soon, heavy swelling forming under his orbital area as the pair traded powerful shots.
Rea, twenty-seven, delivered effective strikes but Arthur, 34, matched the intensity with stinging uppercuts as the pace hardly diminished over twelve rounds.
The victor barely secured the result with official scores of draw, 115-113 and wider gap, but both fighters were relentless and brave, all the qualities their hero Hatton embodied.
