UK light heavyweight Buatsi made a winning yet underwhelming debut to life under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's activity level appeared to earn him a majority decision in a close 10-round contest at the Manchester venue.
But Parker found success, landing some telling single shots in a match where the styles failed to mesh, with frequent clinching disrupting the fight.
The scoring judges scored it 96-94 in favor to the winner, with the final judge a 95-95.
"It wasn't my finest performance but what defines champions? They succeed," Buatsi stated in the arena as he was greeted with negative reactions from the crowd.
The British fighter got back to winning after his maiden career setback - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Several boxing experts believed Parker, 31, merited the decision but the Derbyshire fighter endured the second loss of his 28-match professional journey.
Buatsi Claims Win in Slow Match
His career development has plateaued in recent times through promotional disputes and considerable time of inactivity.
Once tipped as the next star of British boxing, he now stands trying to realize his potential - perhaps in what feels like a last chance - under new promotional backing.
He started carefully, with both competitors ready to overcommit in a calculated opening few rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after damaging his hand in the contest, was making just his second bout at light heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for Buatsi, who utilized a protective stance to barely take the better rounds.
The crowd's patience diminished because of frequent holding, with the challenger going down several times during clinches.
Parker closed well, but several stanzas were difficult to score. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor advances, but with the caliber of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still appears challenging.
Hatton Memorial Motivates Local Rivalry Battle
In the co-main event, Lyndon Arthur beat Bradley Rea by divided decision in a terrific local rivalry battle to win the European light heavyweight championship.
The arena fell silent for a extremely emotional memorial before the fight as a bell ceremony tolled in memory of local hero Hatton, who succumbed aged 46 in September.
It was the first major televised match card in the urban center since Hatton's passing. As the concluding sound ended, the quiet gave way to a chant of "there's just one Ricky Hatton".
The competition during the bout matched the sentiment. The eventual winner was knocked down by a left hook flush on the jaw in the initial stage, getting up unsteadily to his footing on the eight count.
But the red-colored attire of the fighter soon came forward again. Across the ring, Rea - in competitive blue - was damaged soon, noticeable damage developing under his face as the duo exchanged hard punches.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with powerful upward punches as the intensity seldom decreased over 12 rounds.
Arthur barely secured the result with judges scorecards of even score, narrow lead and clearer margin, but each competitor were determined and brave, all the qualities their hero Hatton stood for.
