UK light heavyweight Buatsi earned a win yet underwhelming beginning to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's activity level seemingly secured him a split decision in a close 10-round bout at the Manchester venue.
But Parker landed significant shots, connecting with powerful clean blows in a contest where the styles failed to mesh, with frequent clinching disrupting the fight.
The officials had it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what defines champions? They win," the victor said in the ringside as he was met by negative reactions from the spectators.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with his previous opponent in February - to claim a twentieth professional win.
Some ringside observers felt the challenger, 31, should have been awarded the victory but the Derbyshire fighter endured the second defeat of his 28-fight career.
Buatsi Claims Triumph in Uneventful Encounter
His career development has slowed in recent years through management issues and extended periods of inactivity.
Once tipped as the next star of British boxing, he now finds himself trying to realize his potential - possibly in what appears to be a ultimate opportunity - under recent support.
He opened tentatively, with the two boxers ready to be aggressive in a calculated early stages.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after damaging his hand in the contest, was participating in his second bout at the higher weight class.
By the fight's midpoint, the underdog had kept it close, causing problems for Buatsi, who operated with a protective stance to barely take the better stanzas.
The audience's tolerance wore thin because of regular grabbing, with the challenger falling to the floor several times during clinches.
The underdog finished the stronger, but many rounds were difficult to score. Nevertheless, ex-champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
The victor moves on, but with the presence of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Homage Inspires Local Rivalry Contest
In the supporting bout, Lyndon Arthur defeated Bradley Rea by close verdict in a outstanding all-Manchester battle to secure the continental championship.
The stadium became quiet for a profoundly moving memorial prior to the bout as 10 bells tolled in honor of Manchester's own Ricky Hatton, who passed away aged 46 in recently.
It was the first major televised match card in the urban center since Hatton's death. As the last bell ended, the silence gave way to a chant of "only one Hatton".
The competition inside the ropes matched the feeling. The eventual winner was floored by a powerful punch squarely on the face in the second round, getting up unsteadily to his feet on the count of eight.
But the red-colored equipment of Arthur soon advanced again. From the other corner, Rea - in competitive blue - was injured soon, significant bruising appearing under his face as the fighters landed punishing blows.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, fought fire with fire with stinging uppercuts as the pace seldom decreased over 12 rounds.
The victor narrowly won the decision with official scores of draw, narrow lead and clearer margin, but both fighters were determined and brave, everything their inspiration the legend represented.
