UK light-heavyweight Buatsi secured a victory yet underwhelming start to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level likely gained him a split decision in a tight ten-round bout at the Manchester venue.
But Parker landed significant shots, landing some telling clean blows in a contest where the techniques never quite clicked, with frequent clinching spoiling the contest.
The officials had it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my greatest performance but how do champions respond? They win," the victor commented in the arena as he was greeted with negative reactions from the crowd.
The British fighter bounced back after his initial pro loss - an memorable fight with Callum Smith in February - to secure a twentieth professional win.
Various analysts believed the challenger, 31, deserved the victory but the contender endured the second defeat of his 28-bout professional journey.
The Champion Secures Win in Dull Match
The fighter's advancement has plateaued in the past few years through contract problems and extended periods of lack of fights.
Previously predicted as the rising talent of British boxing, he now stands trying to achieve expectations - perhaps in what feels like a ultimate opportunity - under fresh management.
He opened tentatively, with the two boxers ready to overcommit in a cagey opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in 2022 after suffering a hand injury mid-fight, was making just his second fight at the higher weight class.
By the fight's midpoint, Parker had kept it close, making life awkward for the favorite, who utilized a tight guard to narrowly win the more effective rounds.
The crowd's patience decreased during regular grabbing, with the challenger slipping to the canvas multiple occasions during clinches.
The underdog closed well, but many rounds were hard to judge. However, previous titleholder the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just a single round.
The victor moves on, but with the caliber of heavy hitter David Benavidez, and Russian champion Dmitry Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Homage Inspires Local Rivalry Contest
In the supporting bout, Lyndon Arthur beat Bradley Rea by close verdict in a excellent local rivalry contest to secure the European light heavyweight championship.
The venue grew hushed for a extremely emotional homage prior to the bout as a bell ceremony tolled in remembrance of the city's native Ricky Hatton, who succumbed at age 46 in last month.
It was the premier televised match card in the urban center since Hatton's passing. As the concluding sound faded, the stillness became a shout of "there's just one Ricky Hatton".
The action within the ring matched the emotion. Arthur was knocked down by a significant blow directly to the jaw in the second round, getting up unsteadily to his position on the count of eight.
But the red-colored attire of Arthur soon advanced again. Across the ring, Rea - in rival City blue - was damaged soon, heavy swelling forming under his orbital area as the pair traded punishing blows.
The challenger, twenty-seven, landed power punches but the champion, 34, fought fire with fire with stinging uppercuts as the intensity hardly diminished over twelve rounds.
The victor edged the result with official scores of draw, narrow lead and 115-112, but each competitor were persistent and brave, exactly what their hero Hatton embodied.
