UK light heavyweight Buatsi earned a win yet unimpressive beginning to his career under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a split decision in a competitive ten-round fight at the Co-op Live Arena.
But Parker landed significant shots, delivering effective clean blows in a contest where the approaches failed to mesh, with frequent clinching marring the fight.
The officials had it 96-94 in favor to the winner, with the third a even score.
"It wasn't my greatest performance but how do champions respond? They win," the victor commented in the ring as he was met by disapproval 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 claim a 20th pro success.
Several boxing experts thought Parker, 31, merited the decision but the Derbyshire fighter suffered the second setback of his 28-bout professional journey.
The Champion Claims Victory in Uneventful Match
Buatsi's progress has slowed in the past few years through management issues and considerable time of lack of fights.
Previously predicted as the next star of UK boxing, he now finds himself trying to realize his potential - possibly in what appears to be a final roll of the dice - under recent support.
He began cautiously, with neither fighter prepared to be aggressive in a tentative opening few rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in 2022 after suffering a hand injury during the bout, was making just his second bout at light heavyweight.
By the middle rounds, Parker had made it competitive, making life awkward for the favorite, who operated with a protective stance to narrowly win the cleaner stanzas.
The crowd's patience wore thin during frequent holding, with the challenger going down various instances during clinches.
Parker ended stronger, but several stanzas were difficult to score. Although, former world champion the boxing analyst - working with Dazn - had it significantly in favor for Parker, awarding Buatsi just a single round.
Buatsi progresses, but with the caliber of hard hitter David Benavidez, and Russian star Dmitry Bivol ruling the division, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Homage Motivates All-Manchester Contest
In the co-main event, Lyndon Arthur beat Bradley Rea by split-decision in a terrific all-Manchester contest to win the European light heavyweight title.
The venue grew hushed for a profoundly moving memorial prior to the bout as 10 bells rang in remembrance of the city's native Ricky Hatton, who passed away at age 46 in recently.
It was the premier televised boxing event in the urban center since the passing of Hatton. As the final chime disappeared, the stillness became a shout of "only one Hatton".
The competition within the ring reflected the emotion. Arthur was sent to the canvas by a left hook directly to the jaw in the second round, getting up unsteadily to his feet on the count of eight.
But the traditional red equipment of the fighter soon came forward again. From the other corner, Rea - in competitive blue - was marked up early, heavy swelling appearing under his orbital area as the fighters landed powerful shots.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with powerful upward punches as the action seldom decreased over 12 rounds.
The victor edged the verdict with official scores of even score, 115-113 and wider gap, but both fighters were persistent and full of heart, exactly what their idol the legend stood for.
