UK light heavyweight Buatsi earned a win yet disappointing beginning to his career under recent management with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a tight ten-round bout at the Co-op Live Arena.
But Parker had his moments, landing some telling clean blows in a fight where the techniques never quite clicked, with constant grabbing marring the contest.
The scoring judges scored it 96-94 in favor to Buatsi, with the final judge a 95-95.
"It wasn't my finest performance but how do champions respond? They succeed," Buatsi stated in the ring as he was greeted with negative reactions from the audience.
The British fighter bounced back after his maiden career setback - an memorable fight with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers believed Parker, thirty-one, merited the win but the British boxer suffered the second setback of his 28-bout professional journey.
Buatsi Secures Victory in Uneventful Affair
His career development has slowed in the past few years through contract problems and considerable time of lack of fights.
Once tipped as the rising talent of British boxing, he now finds himself trying to realize his potential - perhaps in what appears to be a last chance - under recent support.
He started carefully, with neither fighter prepared to take risks in a tentative opening few rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after suffering a hand injury during the bout, was participating in his second appearance at the higher weight class.
By the middle rounds, the underdog had made it competitive, making life awkward for Buatsi, who worked behind a solid defense to narrowly win the cleaner stanzas.
The spectators' acceptance wore thin because of regular grabbing, with the challenger going down several times during close exchanges.
Parker finished the stronger, but several stanzas were difficult to score. Nevertheless, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, awarding Buatsi just a single round.
Buatsi progresses, but with the presence of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Memorial Inspires Local Rivalry Battle
In the secondary fight, Arthur defeated Bradley Rea by close verdict in a excellent local rivalry fight to capture the European light-heavyweight title.
The venue fell silent for a profoundly moving homage prior to the bout as 10 bells rang in memory of local hero Ricky Hatton, who succumbed at age 46 in September.
It was the premier televised match card in the city since Hatton's passing. As the concluding sound faded, the quiet became a roar of "there's only one Ricky Hatton".
The action within the ring reflected the feeling. Arthur was knocked down by a left hook flush on the jaw in the initial stage, rising shakily to his feet on the count of eight.
But the red-colored equipment of the fighter soon pressed ahead again. On the opposite side, Rea - in competitive blue - was injured early, significant bruising forming under his orbital area as the pair landed hard punches.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with stinging uppercuts as the action seldom decreased over 12 rounds.
Arthur narrowly won the decision with judges scorecards of 114-114, close margin and 115-112, but both fighters were persistent and full of heart, all the qualities their idol the legend embodied.
