UK light-heavyweight Buatsi made a winning yet unimpressive debut to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a split decision in a competitive 10-round fight at the Co-op Live Arena.
But the challenger landed significant shots, landing some telling single shots in a fight where the styles never quite clicked, with frequent clinching disrupting the contest.
Two judges had it 96-94 for to Buatsi, with the final judge a 95-95.
"It wasn't my best display but what do champions do? They prevail," Buatsi stated in the arena as he was greeted with disapproval from the crowd.
The Londoner got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to earn a 20th career victory.
Various analysts believed the challenger, thirty-one, merited the victory but the Derbyshire fighter suffered the second defeat of his 28-match professional journey.
The Champion Earns Win in Slow Match
The fighter's advancement has slowed in the past few years through promotional disputes and considerable time of inactivity.
Previously predicted as the rising talent of British boxing, he now is positioned trying to realize his potential - perhaps in what seems like a last chance - under recent support.
He began cautiously, with the two boxers ready to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against his former opponent in 2022 after suffering a hand injury during the bout, was competing in only his second fight at light heavyweight.
By the middle rounds, the underdog had stayed in contention, making life awkward for the favorite, who utilized a tight guard to edge the better rounds.
The audience's tolerance decreased amid constant clinching, with Parker slipping to the canvas various instances during clinches.
Parker finished the stronger, but multiple periods were hard to judge. However, former world champion Carl Frampton - working with Dazn - had it significantly in favor for the challenger, giving Buatsi just a single round.
The victor advances, but with the likes of power puncher Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Hatton Memorial Motivates All-Manchester Contest
In the co-main event, Lyndon Arthur defeated Rea by divided decision in a terrific all-Manchester fight to win the European light-heavyweight title.
The arena grew hushed for a extremely emotional memorial prior to the bout as a bell ceremony sounded in honor of local hero Ricky Hatton, who died at age 46 in last month.
It was the premier televised boxing event in the city since the passing of Hatton. As the final chime faded, the silence transitioned to a shout of "there's just one Ricky Hatton".
The competition during the bout reflected the feeling. The eventual winner was knocked down by a powerful punch directly to the jaw in the initial stage, rising shakily to his footing on the count of eight.
But the traditional red shorts of Arthur soon pressed ahead again. Across the ring, Rea - in rival City blue - was injured quickly, significant bruising developing under his eye as the fighters landed hard punches.
The challenger, 27, delivered effective strikes but the champion, 34, fought fire with fire with stinging uppercuts as the action seldom decreased over the full distance.
The victor narrowly won the decision with judges scorecards of 114-114, 115-113 and wider gap, but the two athletes were relentless and full of heart, everything their idol Hatton embodied.
