UK light heavyweight Buatsi made a winning yet unimpressive beginning to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a split decision in a tight 10-round bout at the Co-op Live Arena.
But Parker had his moments, landing some telling clean blows in a match where the approaches failed to mesh, with constant grabbing disrupting the fight.
The scoring judges scored it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my best performance but what do champions do? They succeed," the victor commented in the ring as he was met by negative reactions from the spectators.
The British fighter bounced back after his first professional defeat - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Various analysts felt Parker, thirty-one, deserved the decision but the Derbyshire fighter experienced the second loss of his 28-match career.
Buatsi Secures Win in Slow Match
The fighter's advancement has plateaued in the past few years through promotional disputes and considerable time of inactivity.
Once tipped as the rising talent of British boxing, he now is positioned trying to fulfil that early promise - possibly in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with the two boxers prepared to overcommit in a tentative early stages.
Parker, whose sole prior loss came at super middleweight against his former opponent in 2022 after breaking his hand during the bout, was participating in his second bout at the higher weight class.
By the fight's midpoint, the underdog had stayed in contention, creating difficulties for Buatsi, who utilized a tight guard to barely take the more effective stanzas.
The crowd's patience diminished because of regular grabbing, with the challenger slipping to the canvas multiple occasions during clinches.
The underdog closed well, but several stanzas were difficult to score. However, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for the challenger, giving Buatsi just a single round.
Buatsi progresses, but with the caliber of heavy hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Memorial Inspires Local Rivalry Contest
In the secondary fight, Lyndon Arthur defeated Rea by close verdict in a excellent all-Manchester fight to win the European light heavyweight title.
The arena grew hushed for a deeply poignant tribute prior to the bout as ten bells sounded in remembrance of local hero Ricky Hatton, who succumbed 46 years old in September.
It was the premier televised boxing event in the urban center since Hatton's death. As the final chime faded, the silence gave way to a shout of "only one Hatton".
The fighting within the ring matched the feeling. The eventual winner was sent to the canvas by a left hook directly to the jaw in the early round, rising shakily to his position on the eight count.
But the traditional red shorts of Arthur soon came forward again. On the opposite side, Rea - in opposing blue - was injured soon, noticeable damage forming under his face as the pair landed powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, fought fire with fire with powerful upward punches as the pace seldom decreased over the full distance.
The victor narrowly won the verdict with judges scorecards of even score, close margin and wider gap, but both fighters were persistent and full of heart, everything their hero the legend represented.
