British light-heavyweight Buatsi made a winning yet unimpressive start to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a split decision in a competitive 10-round contest at the Co-op Live Arena.
But the challenger landed significant shots, delivering effective single shots in a fight where the techniques didn't complement each other, with frequent clinching spoiling the action.
The scoring judges judged it 96-94 in favor to the winner, with the remaining official a 95-95.
"It wasn't my greatest performance but what defines champions? They prevail," the victor stated in the arena as he was met by negative reactions from the audience.
The Londoner returned to winning ways after his maiden career setback - an thrilling contest with his previous opponent in February - to claim a 20th career victory.
Various analysts believed Parker, 31, merited the victory but the Derbyshire fighter experienced the second setback of his 28-bout professional journey.
Buatsi Claims Triumph in Slow Encounter
His career development has stalled in recent times through contract problems and long spells of inactivity.
Previously predicted as the rising talent of British boxing, he now finds himself trying to fulfil that early promise - possibly in what seems like a ultimate opportunity - under fresh management.
He started carefully, with the two boxers willing to be aggressive in a calculated opening few rounds.
Parker, whose single earlier setback came at super middleweight against his former opponent in 2022 after breaking his hand mid-fight, was participating in his second appearance at light-heavyweight.
By the middle rounds, Parker had kept it close, causing problems for Buatsi, who utilized a tight guard to barely take the better stanzas.
The spectators' acceptance decreased during frequent holding, with the challenger slipping to the canvas several times during grappling.
Parker ended stronger, but many rounds were hard to judge. However, former world champion the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, scoring for Buatsi just a single round.
Buatsi advances, but with the caliber of power puncher Benavidez, and Russian star Bivol ruling the division, the path to championship success - on this evidence - still looks steep.
Hatton Memorial Motivates Manchester Derby Battle
In the secondary fight, Arthur overcame Bradley Rea by divided decision in a terrific local rivalry battle to capture the continental belt.
The venue fell silent for a extremely emotional homage ahead of the contest as 10 bells tolled in remembrance of local hero Hatton, who passed away at age 46 in last month.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the concluding sound ended, the quiet transitioned to a roar of "there's only one Ricky Hatton".
The action within the ring equaled the feeling. Arthur was knocked down by a left hook directly to the jaw in the second round, rising shakily to his position on the eight count.
But the Manchester United-red attire of Arthur soon came forward again. Across the ring, Rea - in competitive blue - was marked up early, heavy swelling appearing under his orbital area as the fighters traded powerful shots.
The challenger, 27, delivered effective strikes but the champion, thirty-four, matched the intensity with stinging uppercuts as the action seldom decreased over twelve rounds.
Arthur narrowly won the result with official scores of even score, 115-113 and 115-112, but each competitor were relentless and full of heart, all the qualities their idol Hatton represented.
