UK light-heavyweight Buatsi made a winning yet unimpressive debut to life under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a competitive ten-round fight at the Co-op Live Arena.
But Parker landed significant shots, landing some telling individual punches in a fight where the techniques never quite clicked, with constant grabbing spoiling the contest.
The officials had it 96-94 in favor to Buatsi, with the third a even score.
"It wasn't my greatest performance but what defines champions? They win," Buatsi stated in the ringside as he was met by disapproval from the audience.
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.
Various analysts believed the challenger, thirty-one, deserved the win but the British boxer experienced the second defeat of his 28-bout professional journey.
The Champion Secures Victory in Uneventful Encounter
Buatsi's progress has plateaued in recent times through promotional disputes and considerable time of inactivity.
Earlier forecast as the future of UK boxing, he now is positioned trying to realize his potential - possibly in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with both competitors prepared to take risks in a cagey initial rounds.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in 2022 after breaking his hand in the contest, was making just his second appearance at light heavyweight.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for the favorite, who operated with a tight guard to barely take the more effective rounds.
The crowd's patience diminished during constant clinching, with Parker going down various instances during grappling.
The underdog finished the stronger, but several stanzas were difficult to score. Nevertheless, former world champion Carl Frampton - commentating on Dazn - had it particularly wide for Parker, scoring for Buatsi just a single round.
The victor advances, but with the presence of power puncher Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still seems difficult.
Hatton Homage Motivates Manchester Derby Battle
In the secondary fight, Arthur beat Rea by split-decision in a excellent all-Manchester contest to capture the European light-heavyweight championship.
The stadium became quiet for a deeply poignant tribute prior to the bout as ten bells sounded in honor of Manchester's own Hatton, who passed away at age 46 in recently.
It was the premier televised boxing event in the city since Hatton's death. As the last bell disappeared, the silence became a chant of "there's only one Hatton".
The competition during the bout matched the feeling. Arthur was sent to the canvas by a powerful punch flush on the face in the early round, standing uncertainly to his footing on the eight count.
But the Manchester United-red attire of the fighter soon came forward again. Across the ring, Rea - in rival City blue - was marked up early, noticeable damage appearing under his eye as the fighters landed punishing blows.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with stinging uppercuts as the action rarely dropped over 12 rounds.
The victor narrowly won the decision with scoring tallies of 114-114, narrow lead and clearer margin, but the two athletes were determined and brave, all the qualities their inspiration the legend embodied.
