UK light heavyweight Buatsi secured a victory yet unimpressive beginning to life under new promoters with a decision win over Zach Parker in Manchester.
The Olympic medal winner's activity level likely gained him a majority decision in a close ten-round contest at the boxing arena.
But Parker found success, connecting with powerful individual punches in a match where the approaches didn't complement each other, with excessive holding disrupting the action.
Two judges judged it 96-94 to the winner, with the final judge a even score.
"It wasn't my best performance but what defines champions? They win," Buatsi commented in the ringside as he was greeted with disapproval from the audience.
The British fighter bounced back after his first professional defeat - an memorable fight with Callum Smith in February - to claim a twentieth professional win.
Several boxing experts believed the challenger, thirty-one, should have been awarded the victory but the Derbyshire fighter suffered the second defeat of his 28-bout professional journey.
Buatsi Secures Victory in Uneventful Affair
The fighter's advancement has plateaued in recent times through management issues and long spells of lack of fights.
Previously predicted as the next star of the British fight scene, he now stands trying to realize his potential - possibly in what appears to be a ultimate opportunity - under fresh management.
He started carefully, with neither fighter ready to take risks in a calculated opening few rounds.
Parker, whose only previous defeat came at super middleweight against his former opponent in 2022 after damaging his hand in the contest, was participating in his second fight at light-heavyweight.
By the halfway stage, Parker had made it competitive, creating difficulties for the favorite, who utilized a protective stance to barely take the cleaner periods.
The audience's tolerance decreased during frequent holding, with Parker falling to the floor several times during close exchanges.
The underdog closed well, but multiple periods were hard to judge. However, previous titleholder Carl Frampton - commentating on the broadcast network - had it particularly wide for the challenger, giving Buatsi just one round.
Buatsi advances, but with the likes of power puncher David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - based on this performance - still appears challenging.
Ricky Hatton Homage Inspires All-Manchester Contest
In the supporting bout, Arthur defeated Bradley Rea by close verdict in a excellent local rivalry battle to capture the European light-heavyweight title.
The arena grew hushed for a extremely emotional memorial prior to the bout as 10 bells rang in honor of local hero Hatton, who passed away aged 46 in September.
It was the first major televised match card in the urban center since the passing of Hatton. As the concluding sound ended, the quiet transitioned to a shout of "there's just one Ricky Hatton".
The competition during the bout equaled the sentiment. The eventual winner was floored by a significant blow flush on the jaw in the second round, rising shakily to his feet on the count of eight.
But the red-colored shorts of the fighter soon pressed ahead again. Across the ring, the opponent - in rival City blue - was injured early, noticeable damage forming under his orbital area as the fighters traded hard punches.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, fought fire with fire with powerful upward punches as the pace rarely dropped over the full distance.
The victor edged the verdict with scoring tallies of 114-114, close margin and clearer margin, but both fighters were determined and courageous, exactly what their hero the legend embodied.
