UK light heavyweight Buatsi secured a victory yet unimpressive debut to life under new promoters with a points victory over Zach Parker in Manchester.
The Olympic medal winner's activity level likely gained him a majority decision in a close ten-round bout at the Manchester venue.
But the challenger had his moments, connecting with powerful single shots in a match where the approaches failed to mesh, with excessive holding disrupting the fight.
The officials judged it 96-94 to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest performance but what defines champions? They prevail," Buatsi stated in the ringside as he was faced boos from the crowd.
The Londoner got back to winning after his initial pro loss - an epic battle with Callum Smith in last winter - to claim a twentieth professional win.
Some ringside observers believed Parker, 31, should have been awarded the victory but the contender suffered the second loss of his 28-fight career.
The Champion Earns Victory in Dull Match
His career development has stalled in the past few years through contract problems and considerable time of inactivity.
Once tipped as the future of British boxing, he now stands trying to achieve expectations - maybe in what feels like a last chance - under recent support.
He opened tentatively, with the two boxers willing to overcommit in a tentative opening few rounds.
The challenger, whose only previous defeat came at super middleweight against his former opponent in 2022 after breaking his hand mid-fight, was participating in his second bout at the higher weight class.
By the halfway stage, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a protective stance to barely take the cleaner stanzas.
The spectators' acceptance wore thin amid frequent holding, with the challenger falling to the floor multiple occasions during grappling.
Parker finished the stronger, but many rounds were challenging to assess. Although, former world champion Carl Frampton - providing analysis for Dazn - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of heavy hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the path to championship success - judging by this showing - still appears challenging.
Hatton Homage Inspires Local Rivalry Battle
In the co-main event, Arthur overcame Rea by divided decision in a excellent local rivalry contest to secure the European light heavyweight belt.
The venue grew hushed for a extremely emotional tribute before the fight as ten bells sounded in honor of the city's native Hatton, who succumbed at age 46 in last month.
It was the initial significant broadcast match card in the city since Hatton's death. As the last bell disappeared, the silence became a shout of "there's only one Hatton".
The competition within the ring reflected the sentiment. The eventual winner was knocked down by a powerful punch squarely on the jaw in the early round, rising shakily to his position on the count of eight.
But the traditional red shorts of Arthur soon came forward again. On the opposite side, the opponent - in rival City blue - was marked up soon, significant bruising appearing under his eye as the fighters traded punishing blows.
Rea, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with effective uppercuts as the action rarely dropped over twelve rounds.
The victor narrowly won the decision with judges scorecards of draw, narrow lead and wider gap, but each competitor were persistent and full of heart, all the qualities their idol the legend represented.
