British light-heavyweight Buatsi made a winning yet unimpressive start to his career under recent management with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a split decision in a close ten-round contest at the boxing arena.
But Parker found success, connecting with powerful clean blows in a contest where the styles didn't complement each other, with frequent clinching marring the action.
Two judges had it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my greatest display but what do champions do? They succeed," Buatsi commented in the ringside as he was faced boos from the audience.
The British fighter returned to winning ways after his initial pro loss - an epic battle with his previous opponent in last winter - to claim a twentieth professional win.
Several boxing experts felt Parker, thirty-one, merited the win but the contender suffered the second defeat of his 28-bout professional journey.
The Champion Claims Win in Uneventful Encounter
Buatsi's progress has stalled in recent times through management issues and extended periods of inactivity.
Previously predicted as the rising talent of the British fight scene, he now finds himself trying to achieve expectations - maybe in what feels like a ultimate opportunity - under recent support.
He started carefully, with both competitors ready to overcommit in a tentative initial rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after damaging his hand mid-fight, was participating in his second fight at the higher weight class.
By the fight's midpoint, the underdog had kept it close, making life awkward for the favorite, who operated with a protective stance to narrowly win the cleaner rounds.
The audience's tolerance diminished during regular grabbing, with Parker falling to the floor several times during close exchanges.
Parker closed well, but many rounds were hard to judge. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just a single round.
The victor moves on, but with the caliber of power puncher Benavidez, and Russian star Dmitry Bivol ruling the division, the journey to titles - based on this performance - still looks steep.
Hatton Homage Fuels Local Rivalry Battle
In the co-main event, Arthur defeated Bradley Rea by split-decision in a excellent local rivalry battle to secure the continental belt.
The stadium fell silent for a profoundly moving homage prior to the bout as a bell ceremony sounded in honor of Manchester's own Hatton, who passed away at age 46 in September.
It was the first major televised fight night in the location since the passing of Hatton. As the concluding sound faded, the quiet gave way to a shout of "there's only one Ricky Hatton".
The competition during the bout reflected the feeling. Arthur was floored by a powerful punch flush on the chin in the initial stage, standing uncertainly to his position on the eight count.
But the Manchester United-red attire of the fighter soon came forward again. Across the ring, the opponent - in competitive blue - was injured soon, noticeable damage developing under his eye as the fighters landed punishing blows.
The challenger, 27, delivered effective strikes but the champion, thirty-four, responded in kind with effective uppercuts as the pace seldom decreased over the full distance.
The victor narrowly won the result with scoring tallies of draw, close margin and clearer margin, but both fighters were persistent and courageous, exactly what their inspiration Hatton represented.
