British light-heavyweight Buatsi secured a victory yet unimpressive debut to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a close 10-round fight at the boxing arena.
But the challenger found success, delivering effective single shots in a fight where the approaches never quite clicked, with constant grabbing marring the fight.
The officials scored it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest performance but what do champions do? They prevail," the victor said in the ringside as he was faced negative reactions from the crowd.
The Londoner got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to secure a 20th pro success.
Some ringside observers felt Parker, 31, merited the decision but the Derbyshire fighter endured the second setback of his 28-fight career.
The Champion Earns Victory in Slow Encounter
Buatsi's progress has stalled in recent years through management issues and considerable time of lack of fights.
Earlier forecast as the future of UK boxing, he now finds himself trying to fulfil that early promise - possibly in what appears to be a last chance - under fresh management.
He opened tentatively, with the two boxers ready to overcommit in a tentative initial rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in two years ago after suffering a hand injury in the contest, was making just his second fight at light heavyweight.
By the halfway stage, Parker had stayed in contention, creating difficulties for Buatsi, who operated with a solid defense to narrowly win the more effective periods.
The audience's tolerance diminished during constant clinching, with Parker going down several times during close exchanges.
The underdog closed well, but multiple periods were challenging to assess. Although, former world champion the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
The victor progresses, but with the caliber of power puncher Benavidez, and Russian champion Bivol ruling the division, the road to world glory - on this evidence - still looks steep.
Ricky Hatton Homage Motivates Manchester Derby Battle
In the co-main event, Lyndon Arthur beat Bradley Rea by close verdict in a outstanding local rivalry fight to win the European light heavyweight title.
The stadium grew hushed for a deeply poignant memorial before the fight as ten bells rang in memory of Manchester's own Ricky Hatton, who passed away aged 46 in September.
It was the first major televised fight night in the location since Hatton's passing. As the concluding sound ended, the quiet transitioned to a shout of "there's just one Hatton".
The fighting inside the ropes reflected the emotion. Arthur was floored by a left hook directly to the chin in the second round, standing uncertainly to his footing on the count of eight.
But the red-colored shorts of Arthur soon pressed ahead again. On the opposite side, Rea - in competitive blue - was marked up soon, noticeable damage appearing under his eye as the pair landed punishing blows.
Rea, 27, delivered effective strikes but Arthur, thirty-four, matched the intensity with effective uppercuts as the intensity hardly diminished over the full distance.
The victor edged the result with official scores of even score, close margin and clearer margin, but each competitor were persistent and brave, everything their idol Hatton embodied.
