UK light-heavyweight Buatsi earned a win yet underwhelming debut to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a majority decision in a tight 10-round fight at the Co-op Live Arena.
But Parker found success, landing some telling clean blows in a fight where the techniques didn't complement each other, with frequent clinching marring the contest.
The officials had it 96-94 in favor to Buatsi, with the third a 95-95 draw.
"It wasn't my finest showing but what defines champions? They prevail," the victor stated in the ringside as he was greeted with boos from the crowd.
The Londoner returned to winning ways after his initial pro loss - an memorable fight with his previous opponent in last winter - to claim a 20th career victory.
Various analysts felt Parker, thirty-one, merited the win but the British boxer experienced the second setback of his 28-match professional journey.
The Champion Secures Win in Uneventful Encounter
The fighter's advancement has stalled in recent times through promotional disputes and extended periods of inactivity.
Once tipped as the next star of British boxing, he now finds himself trying to achieve expectations - maybe in what feels like a last chance - under fresh management.
He started carefully, with neither fighter ready to overcommit in a cagey initial rounds.
The challenger, whose only previous defeat came at the lower weight class against his former opponent in two years ago after suffering a hand injury mid-fight, was making just his second bout at the higher weight class.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who utilized a protective stance to narrowly win the better rounds.
The crowd's patience wore thin during constant clinching, with Parker going down several times during clinches.
Parker ended stronger, but many rounds were hard to judge. Although, former world champion the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
Buatsi advances, but with the likes of power puncher David Benavidez, and Russian star Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Motivates Local Rivalry Fight
In the secondary fight, Lyndon Arthur overcame Bradley Rea by split-decision in a outstanding local rivalry battle to capture the European light-heavyweight championship.
The arena fell silent for a profoundly moving tribute prior to the bout as 10 bells tolled in honor of local hero Hatton, who passed away aged 46 in recently.
It was the premier televised boxing event in the city since Hatton's death. As the final chime disappeared, the quiet gave way to a shout of "there's just one Hatton".
The fighting during the bout reflected the feeling. Arthur was sent to the canvas by a significant blow squarely on the jaw in the early round, standing uncertainly to his position on the referee's count.
But the red-colored equipment of Arthur soon advanced again. Across the ring, Rea - in opposing blue - was marked up quickly, heavy swelling appearing under his eye as the duo traded punishing blows.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, fought fire with fire with powerful upward punches as the intensity rarely dropped over 12 rounds.
The victor narrowly won the verdict with scoring tallies of draw, narrow lead and 115-112, but each competitor were relentless and brave, all the qualities their idol the legend stood for.
