British light-heavyweight Buatsi earned a win yet disappointing debut to his career under new promoters with a decision win over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a majority decision in a competitive 10-round bout at the boxing arena.
But the challenger found success, connecting with powerful individual punches in a fight where the techniques never quite clicked, with excessive holding disrupting the fight.
Two judges judged it 96-94 for to the winner, with the third a 95-95 draw.
"It wasn't my best showing but what do champions do? They succeed," Buatsi commented in the ring as he was greeted with boos from the audience.
The Londoner bounced back after his initial pro loss - an memorable fight with Callum Smith in last winter - to earn a twentieth professional win.
Some ringside observers thought Parker, thirty-one, deserved the victory but the British boxer suffered the second loss of his 28-fight career.
The Champion Claims Victory in Uneventful Affair
The fighter's advancement has slowed in recent years through management issues and long spells of inactivity.
Once tipped as the future of UK boxing, he now is positioned trying to achieve expectations - perhaps in what seems like a last chance - under recent support.
He opened tentatively, with the two boxers prepared to overcommit in a calculated opening few rounds.
Parker, whose only previous defeat came at super-middleweight against John Ryder in 2022 after damaging his hand during the bout, was making just his second bout at light-heavyweight.
By the halfway stage, Parker had kept it close, causing problems for Buatsi, who utilized a tight guard to barely take the more effective periods.
The audience's tolerance diminished amid frequent holding, with Parker falling to the floor various instances during grappling.
The underdog ended stronger, but several stanzas were hard to judge. Nevertheless, former world champion the boxing analyst - working with Dazn - had it significantly in favor for the challenger, scoring for Buatsi just one round.
The victor progresses, but with the likes of power puncher David Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Hatton Memorial Motivates Manchester Derby Fight
In the supporting bout, Arthur overcame Rea by close verdict in a excellent Manchester vs Manchester fight to capture the European light-heavyweight title.
The stadium fell silent for a extremely emotional memorial prior to the bout as ten bells sounded in memory of Manchester's own Hatton, who passed away aged 46 in recently.
It was the first major televised boxing event in the location since Hatton's death. As the final chime faded, the stillness transitioned to a roar of "there's only one Hatton".
The competition during the bout equaled the sentiment. The eventual winner was floored by a left hook squarely on the chin in the initial stage, getting up unsteadily to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. Across the ring, Rea - in rival City blue - was damaged early, significant bruising developing under his orbital area as the fighters exchanged powerful shots.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, matched the intensity with powerful upward punches as the pace seldom decreased over 12 rounds.
The victor narrowly won the result with scoring tallies of 114-114, narrow lead and clearer margin, but each competitor were relentless and courageous, everything their inspiration the legend represented.
