UK light-heavyweight Buatsi secured a victory yet underwhelming debut to his career under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output seemingly secured him a judges' verdict in a competitive ten-round contest at the Manchester venue.
But the challenger had his moments, landing some telling clean blows in a fight where the techniques never quite clicked, with excessive holding marring the action.
Two judges judged it 96-94 for to the winner, with the final judge a even score.
"It wasn't my best showing but what do champions do? They succeed," Buatsi commented in the ring as he was greeted with boos from the audience.
The British fighter bounced back after his initial pro loss - an thrilling contest with Callum Smith in February - to secure a 20th pro success.
Several boxing experts thought the challenger, 31, should have been awarded the decision but the contender suffered the second setback of his 28-match career.
Buatsi Secures Win in Dull Affair
Buatsi's progress has stalled in recent years through management issues and considerable time of inactivity.
Earlier forecast as the future of British boxing, he now finds himself trying to realize his potential - maybe in what appears to be a ultimate opportunity - under fresh management.
He opened tentatively, with neither fighter prepared to overcommit in a calculated opening few rounds.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago after damaging his hand in the contest, was making just his second fight at light heavyweight.
By the middle rounds, Parker had kept it close, making life awkward for the favorite, who worked behind a solid defense to narrowly win the cleaner stanzas.
The crowd's patience decreased during regular grabbing, with the challenger slipping to the canvas multiple occasions during close exchanges.
Parker closed well, but multiple periods were hard to judge. Nevertheless, previous titleholder the boxing analyst - working with the broadcast network - had it strongly leaning for the challenger, giving Buatsi just one round.
The victor moves on, but with the caliber of hard hitter Benavidez, and Russian star Dmitry Bivol dominating the weight class, the journey to titles - based on this performance - still looks steep.
Hatton Homage Inspires Manchester Derby Fight
In the supporting bout, Arthur defeated Bradley Rea by split-decision in a outstanding local rivalry contest to capture the continental championship.
The arena became quiet for a deeply poignant homage prior to the bout as a bell ceremony rang in memory of Manchester's own Ricky Hatton, who died at age 46 in September.
It was the premier televised boxing event in the city since the passing of Hatton. As the concluding sound ended, the quiet gave way to a roar of "there's just one Hatton".
The action within the ring matched the sentiment. Arthur was sent to the canvas by a powerful punch flush on the face in the initial stage, rising shakily to his position on the count of eight.
But the Manchester United-red attire of the fighter soon advanced again. From the other corner, Rea - in rival City blue - was damaged soon, significant bruising appearing under his orbital area as the fighters landed powerful shots.
Rea, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the intensity seldom decreased over the full distance.
The victor edged the decision with judges scorecards of draw, close margin and clearer margin, but the two athletes were persistent and courageous, all the qualities their hero Hatton embodied.
