British light-heavyweight Buatsi earned a win yet underwhelming beginning to life under fresh promotional backing with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a close ten-round contest at the Co-op Live Arena.
But Parker landed significant shots, connecting with powerful clean blows in a contest where the techniques didn't complement each other, with excessive holding spoiling 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 finest display but what do champions do? They prevail," Buatsi commented in the ringside as he was faced boos from the crowd.
The Londoner got back to winning after his maiden career setback - an epic battle with Callum Smith in last winter - to earn a 20th pro success.
Several boxing experts believed Parker, 31, deserved the decision but the British boxer endured the second loss of his 28-fight professional journey.
The Champion Earns Win in Dull Encounter
His career development has plateaued in recent years through promotional disputes and extended periods of inactivity.
Once tipped as the next star of the British fight scene, he now finds himself trying to fulfil that early promise - maybe in what feels like a last chance - under fresh management.
He opened tentatively, with neither fighter prepared to take risks in a tentative early stages.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in two years ago after damaging his hand mid-fight, was participating in his second fight at light-heavyweight.
By the middle rounds, Parker had made it competitive, creating difficulties for Buatsi, who operated with a tight guard to narrowly win the better rounds.
The spectators' acceptance wore thin amid regular grabbing, with Parker falling to the floor various instances during close exchanges.
The underdog closed well, but several stanzas were hard to judge. Although, former world champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for Parker, giving Buatsi just a single round.
Buatsi advances, but with the likes of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the path to championship success - on this evidence - still seems difficult.
Hatton Memorial Inspires Local Rivalry Contest
In the secondary fight, Arthur beat Rea by divided decision in a outstanding local rivalry fight to win the continental title.
The arena fell silent for a extremely emotional homage prior to the bout as ten bells sounded in remembrance of the city's native Ricky Hatton, who passed away aged 46 in last month.
It was the initial significant broadcast fight night in the location since Hatton's death. As the final chime faded, the quiet transitioned to a shout of "there's just one Hatton".
The competition inside the ropes equaled the sentiment. The eventual winner was sent to the canvas by a significant blow flush on the face in the second round, standing uncertainly to his feet on the count of eight.
But the red-colored attire of the fighter soon came forward again. On the opposite side, the opponent - in opposing blue - was marked up quickly, significant bruising appearing under his orbital area as the duo landed hard punches.
Rea, 27, connected with strong blows but Arthur, 34, matched the intensity with powerful upward punches as the intensity rarely dropped over twelve rounds.
Arthur edged the result with scoring tallies of even score, close margin and clearer margin, but both fighters were persistent and courageous, exactly what their inspiration the legend stood for.
