UK light heavyweight Buatsi made a winning yet unimpressive debut to life under recent management with a decision win 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 Manchester venue.
But the challenger had his moments, landing some telling single shots in a fight where the approaches didn't complement each other, with constant grabbing marring the fight.
Two judges had it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my best showing but how do champions respond? They prevail," the victor stated in the ringside as he was met by boos from the audience.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in February - to claim a 20th pro success.
Various analysts believed the challenger, thirty-one, should have been awarded the decision but the contender endured the second setback of his 28-bout professional journey.
The Champion Claims Victory in Dull Affair
His career development has plateaued in recent years through contract problems and long spells of inactivity.
Previously predicted as the next star of British boxing, he now finds himself trying to realize his potential - maybe in what seems like a ultimate opportunity - under new promotional backing.
He began cautiously, with both competitors prepared to take risks in a tentative initial rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was participating in his second fight at light-heavyweight.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a tight guard to narrowly win the more effective rounds.
The crowd's patience wore thin amid regular grabbing, with Parker falling to the floor several times during close exchanges.
Parker ended stronger, but many rounds were challenging to assess. Although, former world champion Carl Frampton - commentating on the broadcast network - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor progresses, but with the presence of heavy hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Homage Fuels Manchester Derby Fight
In the secondary fight, Lyndon Arthur overcame Rea by close verdict in a excellent local rivalry battle to capture the European light heavyweight title.
The stadium became quiet for a extremely emotional homage before the fight as 10 bells rang in memory of the city's native Ricky Hatton, who succumbed at age 46 in September.
It was the premier televised fight night in the location since Hatton's passing. As the final chime ended, the quiet transitioned to a roar of "there's just one Hatton".
The action within the ring matched the feeling. The eventual winner was sent to the canvas by a left hook squarely on the face in the second round, standing uncertainly to his feet on the referee's count.
But the Manchester United-red attire of Arthur soon advanced again. On the opposite side, the opponent - in competitive blue - was injured soon, heavy swelling developing under his face as the duo traded punishing blows.
Rea, 27, landed power punches but the champion, thirty-four, matched the intensity with effective uppercuts as the intensity seldom decreased over twelve rounds.
Arthur edged the verdict with official scores of 114-114, narrow lead and clearer margin, but both fighters were determined and courageous, all the qualities their inspiration Hatton embodied.
