British light heavyweight Buatsi made a winning yet unimpressive beginning to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's work rate seemingly secured him a judges' verdict in a tight ten-round bout at the Co-op Live Arena.
But the challenger had his moments, delivering effective single shots in a match where the techniques didn't complement each other, with excessive holding marring the fight.
The officials judged it 96-94 to the winner, with the remaining official a 95-95.
"It wasn't my finest showing but what do champions do? They prevail," Buatsi stated in the ring as he was met by boos from the spectators.
The Londoner bounced back after his initial pro loss - an epic battle with Callum Smith in February - to secure a 20th career victory.
Some ringside observers felt the challenger, thirty-one, deserved the win but the British boxer suffered the second defeat of his 28-bout career.
Buatsi Earns Win in Uneventful Match
His career development has slowed in recent times through contract problems and long spells of inactivity.
Earlier forecast as the rising talent of the British fight scene, he now stands trying to achieve expectations - maybe in what feels like a ultimate opportunity - under fresh management.
He opened tentatively, with both competitors willing to be aggressive in a tentative opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in 2022 after suffering a hand injury mid-fight, was competing in only his second appearance at light-heavyweight.
By the fight's midpoint, Parker had made it competitive, making life awkward for the favorite, who operated with a solid defense to narrowly win the more effective periods.
The audience's tolerance wore thin because of constant clinching, with Parker going down several times during clinches.
The underdog closed well, but many rounds were difficult to score. However, ex-champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for Parker, awarding Buatsi just only one stanza.
Buatsi progresses, but with the caliber of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Homage Motivates Local Rivalry Fight
In the secondary fight, Arthur beat Rea by split-decision in a terrific Manchester vs Manchester contest to win the European light heavyweight title.
The stadium grew hushed for a extremely emotional homage before the fight as a bell ceremony rang in remembrance of the city's native Ricky Hatton, who passed away 46 years old in September.
It was the initial significant broadcast boxing event in the location since Hatton's passing. As the concluding sound disappeared, the stillness became a chant of "there's only one Hatton".
The action inside the ropes matched the feeling. The eventual winner was knocked down by a left hook directly to the jaw in the second round, rising shakily to his footing on the eight count.
But the red-colored shorts of the fighter soon came forward again. On the opposite side, Rea - in competitive blue - was marked up soon, heavy swelling developing under his face as the duo exchanged powerful shots.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with stinging uppercuts as the action hardly diminished over 12 rounds.
Arthur edged the decision with scoring tallies of draw, narrow lead and clearer margin, but both fighters were determined and full of heart, all the qualities their hero Hatton represented.
