UK light heavyweight Buatsi made a winning yet unimpressive debut to life under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a judges' verdict in a competitive ten-round fight at the Co-op Live Arena.
But Parker had his moments, landing some telling individual punches in a contest where the styles didn't complement each other, with constant grabbing spoiling the action.
The officials scored it 96-94 to the winner, with the third a 95-95 draw.
"It wasn't my greatest display but what do champions do? They win," Buatsi said in the ring as he was faced disapproval from the crowd.
The British fighter bounced back after his first professional defeat - an memorable fight with his previous opponent in February - to earn a 20th career victory.
Various analysts felt the challenger, 31, deserved the victory but the Derbyshire fighter experienced the second setback of his 28-match professional journey.
Buatsi Secures Win in Uneventful Encounter
The fighter's advancement has plateaued in recent times through management issues and considerable time of inactivity.
Earlier forecast as the rising talent of UK boxing, he now stands trying to fulfil that early promise - possibly in what seems like a final roll of the dice - under fresh management.
He started carefully, with the two boxers prepared to take risks in a calculated opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against John Ryder in 2022 after breaking his hand mid-fight, was participating in his second fight at the higher weight class.
By the fight's midpoint, Parker had stayed in contention, making life awkward for the favorite, who worked behind a solid defense to narrowly win the better periods.
The audience's tolerance diminished amid regular grabbing, with the challenger going down various instances during close exchanges.
The underdog ended stronger, but multiple periods were hard to judge. Nevertheless, former world champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just a single round.
The victor advances, but with the presence of power puncher Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - judging by this showing - still looks steep.
Hatton Memorial Inspires Local Rivalry Battle
In the secondary fight, Arthur beat Bradley Rea by divided decision in a terrific local rivalry battle to capture the European light-heavyweight championship.
The arena became quiet for a extremely emotional memorial before the fight as ten bells sounded in remembrance of Manchester's own Hatton, who died aged 46 in September.
It was the first major televised boxing event in the city since Hatton's death. As the last bell disappeared, the stillness transitioned to a chant of "only one Ricky Hatton".
The action inside the ropes matched the feeling. Arthur was sent to the canvas by a left hook flush on the jaw in the initial stage, rising shakily to his footing on the eight count.
But the traditional red shorts of the fighter soon came forward again. From the other corner, Rea - in rival City blue - was damaged quickly, noticeable damage developing under his eye as the fighters exchanged hard punches.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, matched the intensity with powerful upward punches as the action rarely dropped over twelve rounds.
Arthur narrowly won the decision with scoring tallies of 114-114, 115-113 and wider gap, but the two athletes were determined and courageous, all the qualities their inspiration the legend represented.
