UK light-heavyweight Buatsi made a winning yet underwhelming beginning to life under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a split decision in a competitive ten-round bout at the Manchester venue.
But Parker found success, connecting with powerful single shots in a match where the approaches never quite clicked, with excessive holding spoiling the fight.
The officials judged it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest showing but how do champions respond? They win," the victor commented in the ring as he was met by negative reactions from the spectators.
The British fighter returned to winning ways after his maiden career setback - an thrilling contest with his previous opponent in last winter - to claim a 20th pro success.
Some ringside observers thought the challenger, thirty-one, deserved the win but the Derbyshire fighter experienced the second setback of his 28-fight professional journey.
The Champion Earns Win in Slow Match
Buatsi's progress has plateaued in the past few years through contract problems and extended periods of inactivity.
Once tipped as the future of the British fight scene, he now stands trying to achieve expectations - perhaps in what feels like a ultimate opportunity - under recent support.
He began cautiously, with the two boxers willing to be aggressive in a calculated early stages.
Parker, whose sole prior loss came at super-middleweight against John Ryder in two years ago after breaking his hand in the contest, was participating in his second appearance at the higher weight class.
By the fight's midpoint, Parker had made it competitive, causing problems for the favorite, who worked behind a protective stance to narrowly win the cleaner stanzas.
The crowd's patience decreased amid frequent holding, with Parker falling to the floor several times during grappling.
The underdog closed well, but several stanzas were hard to judge. However, ex-champion the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for the challenger, scoring for Buatsi just one round.
The victor progresses, but with the caliber of power puncher David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the path to championship success - judging by this showing - still seems difficult.
Ricky Hatton Memorial Fuels Local Rivalry Battle
In the supporting bout, Lyndon Arthur beat Bradley Rea by close verdict in a excellent local rivalry battle to win the European light-heavyweight championship.
The stadium grew hushed for a extremely emotional homage ahead of the contest as ten bells rang in remembrance of the city's native Hatton, who died aged 46 in September.
It was the first major televised boxing event in the location since Hatton's passing. As the final chime faded, the silence became a chant of "there's only one Hatton".
The action within the ring matched the sentiment. Arthur was knocked down by a significant blow directly to the jaw in the early round, rising shakily to his feet on the referee's count.
But the red-colored attire of the fighter soon advanced again. On the opposite side, the opponent - in competitive blue - was damaged early, heavy swelling forming under his orbital area as the pair traded punishing blows.
The challenger, 27, connected with strong blows but Arthur, thirty-four, responded in kind with stinging uppercuts as the pace hardly diminished over twelve rounds.
The victor barely secured the verdict with scoring tallies of 114-114, 115-113 and wider gap, but both fighters were persistent and courageous, all the qualities their idol Hatton represented.
