British light heavyweight Buatsi secured a victory yet disappointing beginning to life under new promoters with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a competitive ten-round fight at the boxing arena.
But the challenger found success, delivering effective single shots in a fight where the styles didn't complement each other, with excessive holding disrupting the action.
The officials scored it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest showing but how do champions respond? They succeed," Buatsi commented in the ring as he was faced boos from the spectators.
The British fighter returned to winning ways after his maiden career setback - an epic battle with his previous opponent in last winter - to earn a twentieth professional win.
Several boxing experts felt the challenger, 31, merited the decision but the British boxer suffered the second defeat of his 28-bout career.
Buatsi Secures Triumph in Uneventful Match
His career development has slowed in the past few years through promotional disputes and extended periods of inactivity.
Previously predicted as the rising talent of British boxing, he now is positioned trying to achieve expectations - perhaps in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter ready to be aggressive in a tentative initial rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was competing in only his second bout at the higher weight class.
By the middle rounds, Parker had stayed in contention, creating difficulties for the favorite, who worked behind a protective stance to barely take the more effective rounds.
The crowd's patience wore thin because of regular grabbing, with Parker slipping to the canvas multiple occasions during grappling.
The underdog finished the stronger, but many rounds were hard to judge. Although, ex-champion the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor moves on, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Tribute Motivates Manchester Derby Contest
In the secondary fight, Lyndon Arthur defeated Rea by divided decision in a excellent local rivalry fight to capture the European light heavyweight title.
The stadium fell silent for a profoundly moving memorial ahead of the contest as 10 bells sounded in memory of the city's native Hatton, who died at age 46 in September.
It was the premier televised boxing event in the city since Hatton's passing. As the concluding sound disappeared, the silence transitioned to a roar of "there's just one Hatton".
The competition during the bout equaled the feeling. The eventual winner was floored by a significant blow squarely on the jaw in the early round, rising shakily to his position on the count of eight.
But the traditional red shorts of Arthur soon advanced again. Across the ring, the opponent - in competitive blue - was marked up early, noticeable damage appearing under his eye as the duo exchanged hard punches.
Rea, 27, landed power punches but Arthur, thirty-four, responded in kind with stinging uppercuts as the intensity seldom decreased over the full distance.
Arthur narrowly won the decision with judges scorecards of even score, narrow lead and wider gap, but the two athletes were determined and full of heart, all the qualities their hero the legend embodied.
