UK light-heavyweight Buatsi made a winning yet disappointing beginning to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a majority decision in a tight ten-round fight at the Manchester venue.
But Parker landed significant shots, delivering effective individual punches in a match where the styles failed to mesh, with frequent clinching marring the fight.
The scoring judges had it 96-94 to the winner, with the final judge a even score.
"It wasn't my best display but what do champions do? They succeed," Buatsi said in the arena as he was faced negative reactions from the audience.
The Londoner returned to winning ways after his maiden career setback - an thrilling contest with his previous opponent in last winter - to earn a twentieth professional win.
Several boxing experts felt the challenger, thirty-one, deserved the victory but the contender endured the second setback of his 28-match professional journey.
Buatsi Secures Win in Dull Encounter
Buatsi's progress has stalled in recent times through promotional disputes and extended periods of lack of fights.
Once tipped as the rising talent of UK boxing, he now finds himself trying to realize his potential - maybe in what feels like a last chance - under fresh management.
He began cautiously, with both competitors willing to overcommit in a tentative opening few rounds.
Parker, whose single earlier setback came at the lower weight class against John Ryder in 2022 after damaging his hand in the contest, was competing in only his second fight at light-heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for the favorite, who worked behind a tight guard to barely take the better stanzas.
The spectators' acceptance wore thin because of regular grabbing, with the challenger going down several times during close exchanges.
The underdog ended stronger, but several stanzas were hard to judge. Although, ex-champion the boxing analyst - providing analysis for Dazn - had it significantly in favor for Parker, awarding Buatsi just only one stanza.
The victor moves on, but with the likes of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - on this evidence - still seems difficult.
Ricky Hatton Memorial Motivates Manchester Derby Contest
In the secondary fight, Arthur overcame Bradley Rea by split-decision in a terrific Manchester vs Manchester fight to secure the European light heavyweight championship.
The venue became quiet for a extremely emotional memorial ahead of the contest as a bell ceremony rang in honor of Manchester's own Ricky Hatton, who succumbed at age 46 in recently.
It was the premier televised match card in the urban center since the passing of Hatton. As the final chime ended, the quiet became a roar of "only one Hatton".
The action within the ring matched the feeling. Arthur was floored by a powerful punch squarely on the jaw in the early round, getting up unsteadily to his position on the count of eight.
But the traditional red attire of the fighter soon pressed ahead again. On the opposite side, Rea - in opposing blue - was marked up soon, heavy swelling appearing under his face as the pair exchanged powerful shots.
The challenger, 27, connected with strong blows but Arthur, 34, fought fire with fire with powerful upward punches as the pace rarely dropped over twelve rounds.
The victor edged the decision with judges scorecards of 114-114, close margin and clearer margin, but the two athletes were determined and courageous, all the qualities their inspiration Hatton stood for.
