UK light-heavyweight Buatsi secured a victory yet unimpressive start to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a split decision in a tight ten-round fight at the boxing arena.
But Parker had his moments, delivering effective individual punches in a fight where the techniques failed to mesh, with frequent clinching disrupting the action.
The officials scored it 96-94 to Buatsi, with the third a 95-95.
"It wasn't my finest performance but what do champions do? They prevail," the victor commented in the arena as he was met by negative reactions from the crowd.
The Londoner bounced back after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a 20th pro success.
Some ringside observers thought Parker, thirty-one, deserved the victory but the contender endured the second setback of his 28-match career.
Buatsi Secures Triumph in Slow Affair
Buatsi's progress has plateaued in the past few years through promotional disputes and extended periods of lack of fights.
Once tipped as the rising talent of British boxing, he now finds himself trying to fulfil that early promise - possibly in what feels like a ultimate opportunity - under fresh management.
He opened tentatively, with neither fighter willing to be aggressive in a cagey opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in 2022 after damaging his hand during the bout, was participating in his second bout at the higher weight class.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who operated with a protective stance to barely take the better periods.
The crowd's patience wore thin during regular grabbing, with the challenger slipping to the canvas several times during grappling.
The underdog ended stronger, but many rounds were challenging to assess. Nevertheless, previous titleholder the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, awarding Buatsi just a single round.
Buatsi progresses, but with the presence of heavy hitter Benavidez, and Eastern European fighter Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Hatton Homage Inspires Local Rivalry Battle
In the secondary fight, Lyndon Arthur defeated Bradley Rea by split-decision in a terrific all-Manchester fight to capture the European light heavyweight belt.
The arena grew hushed for a extremely emotional homage ahead of the contest as a bell ceremony tolled in remembrance of local hero Ricky Hatton, who passed away 46 years old in last month.
It was the premier televised fight night in the urban center since the passing of Hatton. As the last bell disappeared, the stillness transitioned to a chant of "only one Hatton".
The competition within the ring equaled the emotion. Arthur was sent to the canvas by a significant blow flush on the chin in the early round, rising shakily to his footing on the eight count.
But the traditional red equipment of Arthur soon advanced again. On the opposite side, the opponent - in opposing blue - was injured early, heavy swelling forming under his eye as the fighters landed hard punches.
The challenger, twenty-seven, delivered effective strikes but the champion, thirty-four, matched the intensity with stinging uppercuts as the pace rarely dropped over twelve rounds.
Arthur narrowly won the result with judges scorecards of even score, close margin and 115-112, but each competitor were determined and courageous, exactly what their inspiration the legend embodied.
