British 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 activity level appeared to earn him a split decision in a tight ten-round fight at the Manchester venue.
But Parker found success, landing some telling single shots in a contest where the styles never quite clicked, with excessive holding marring the action.
The officials scored it 96-94 for to the winner, with the third a even score.
"It wasn't my finest performance but what do champions do? They win," Buatsi said in the ringside as he was met by negative reactions from the audience.
The British fighter bounced back after his first professional defeat - an epic battle with Callum Smith in last winter - to claim a 20th pro success.
Some ringside observers thought Parker, thirty-one, deserved the decision but the Derbyshire fighter endured the second setback of his 28-fight professional journey.
Buatsi Earns Victory in Dull Affair
The fighter's advancement has stalled in recent times through promotional disputes and long spells of inactivity.
Previously predicted as the rising talent of British boxing, he now stands trying to realize his potential - possibly in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with the two boxers willing to take risks in a tentative early stages.
The challenger, whose only previous defeat came at the lower weight class 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 worked behind a tight guard to barely take the more effective rounds.
The spectators' acceptance wore thin because of frequent holding, with Parker falling to the floor several times during close exchanges.
The underdog finished the stronger, but many rounds were challenging to assess. Nevertheless, ex-champion the boxing analyst - working with the broadcast network - had it strongly leaning for the challenger, giving Buatsi just only one stanza.
The victor moves on, but with the presence of power puncher Benavidez, and Russian star Bivol ruling the division, the journey to titles - on this evidence - still seems difficult.
Ricky Hatton Homage Motivates Manchester Derby Contest
In the secondary fight, Lyndon Arthur beat Rea by close verdict in a excellent all-Manchester battle to win the European light heavyweight belt.
The stadium grew hushed for a deeply poignant tribute before the fight as 10 bells rang in honor of Manchester's own Ricky Hatton, who passed away 46 years old in recently.
It was the premier televised boxing event in the location since the passing of Hatton. As the last bell ended, the silence became a chant of "only one Ricky Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was sent to the canvas by a powerful punch squarely on the jaw in the second round, getting up unsteadily to his feet on the count of eight.
But the Manchester United-red attire of the fighter soon pressed ahead again. Across the ring, Rea - in rival City blue - was injured quickly, noticeable damage appearing under his orbital area as the duo exchanged punishing blows.
The challenger, 27, delivered effective strikes but Arthur, 34, matched the intensity with effective uppercuts as the pace seldom decreased over 12 rounds.
The victor edged the verdict with scoring tallies of even score, narrow lead and clearer margin, but the two athletes were determined and full of heart, exactly what their idol the legend stood for.
