British light heavyweight Buatsi made a winning yet unimpressive debut to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a judges' verdict in a competitive 10-round contest at the Co-op Live Arena.
But the challenger found success, connecting with powerful clean blows in a match where the approaches didn't complement each other, with excessive holding disrupting the action.
Two judges scored it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what defines champions? They win," Buatsi said in the ringside as he was met by disapproval from the spectators.
The British fighter returned to winning ways after his initial pro loss - an memorable fight with Callum Smith in February - to earn a 20th career victory.
Various analysts felt the challenger, thirty-one, deserved the decision but the British boxer endured the second setback of his 28-fight professional journey.
The Champion Earns Victory in Uneventful Affair
The fighter's advancement has stalled in recent times through promotional disputes and extended periods of inactivity.
Earlier forecast as the future of British boxing, he now is positioned trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with neither fighter ready to be aggressive in a tentative early stages.
The challenger, whose sole prior loss came at super-middleweight against his former opponent in two years ago after suffering a hand injury during the bout, was making just his second appearance at light-heavyweight.
By the halfway stage, the underdog had kept it close, causing problems for the favorite, who worked behind a protective stance to barely take the cleaner rounds.
The spectators' acceptance wore thin amid regular grabbing, with the challenger falling to the floor various instances during close exchanges.
The underdog finished the stronger, but many rounds were hard to judge. Nevertheless, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, scoring for Buatsi just one round.
Buatsi advances, but with the likes of heavy hitter David Benavidez, and Eastern European fighter Bivol dominating the weight class, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Homage Motivates Manchester Derby Battle
In the supporting bout, Lyndon Arthur defeated Rea by divided decision in a outstanding local rivalry battle to capture the European light-heavyweight title.
The arena grew hushed for a extremely emotional homage prior to the bout as a bell ceremony tolled in memory of Manchester's own Hatton, who succumbed at age 46 in September.
It was the premier televised match card in the urban center since the passing of Hatton. As the final chime disappeared, the stillness gave way to a chant of "there's just one Hatton".
The fighting within the ring reflected the sentiment. The eventual winner was floored by a left hook squarely on the face in the initial stage, getting up unsteadily to his footing on the eight count.
But the traditional red shorts of the fighter soon came forward again. On the opposite side, the opponent - in opposing blue - was marked up soon, noticeable damage forming under his face as the duo traded powerful shots.
The challenger, twenty-seven, landed power punches but Arthur, 34, responded in kind with powerful upward punches as the action seldom decreased over 12 rounds.
The victor narrowly won the result with judges scorecards of even score, 115-113 and wider gap, but the two athletes were determined and courageous, everything their hero the legend stood for.
