British light-heavyweight Buatsi earned a win yet unimpressive beginning to his career under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic medal winner's work rate likely gained him a judges' verdict in a tight ten-round bout at the Manchester venue.
But Parker had his moments, connecting with powerful clean blows in a contest where the techniques didn't complement each other, with frequent clinching disrupting the contest.
The officials scored it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my finest performance but what defines champions? They succeed," Buatsi stated in the ringside as he was faced boos from the spectators.
The Londoner bounced back after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a twentieth professional win.
Several boxing experts felt the challenger, 31, should have been awarded the victory but the Derbyshire fighter suffered the second setback of his 28-match professional journey.
The Champion Claims Win 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 future of UK boxing, he now finds himself trying to fulfil that early promise - possibly in what feels like a final roll of the dice - under fresh management.
He began cautiously, with the two boxers ready to be aggressive in a cagey early stages.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after damaging his hand mid-fight, was competing in only his second fight at light heavyweight.
By the halfway stage, Parker had stayed in contention, making life awkward for Buatsi, who operated with a protective stance to barely take the more effective rounds.
The crowd's patience wore thin because of regular grabbing, with Parker falling to the floor multiple occasions during close exchanges.
The underdog closed well, but many rounds were difficult to score. Nevertheless, ex-champion the boxing analyst - providing analysis for the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of heavy hitter David Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Memorial Fuels Manchester Derby Fight
In the secondary fight, Arthur overcame Bradley Rea by split-decision in a terrific local rivalry fight to win the European light heavyweight championship.
The arena fell silent for a deeply poignant memorial before the fight as 10 bells tolled in remembrance of Manchester's own Hatton, who passed away 46 years old in September.
It was the initial significant broadcast boxing event in the city since the passing of Hatton. As the concluding sound disappeared, the stillness transitioned to a roar of "only one Ricky Hatton".
The fighting inside the ropes reflected the emotion. Arthur was knocked down by a significant blow directly to the face in the early round, rising shakily to his feet on the count of eight.
But the red-colored shorts of Arthur soon advanced again. On the opposite side, Rea - in rival City blue - was marked up quickly, heavy swelling forming under his eye as the fighters exchanged punishing blows.
Rea, twenty-seven, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the action rarely dropped over the full distance.
Arthur narrowly won the result with official scores of 114-114, 115-113 and 115-112, but both fighters were determined and brave, all the qualities their idol the legend represented.
