British light heavyweight Buatsi made a winning yet unimpressive debut to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a competitive 10-round fight at the Manchester venue.
But Parker landed significant shots, delivering effective individual punches in a fight where the techniques never quite clicked, with excessive holding marring the action.
The scoring judges had it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest performance but what do champions do? They prevail," Buatsi said in the ring as he was met by disapproval from the crowd.
The Londoner bounced back after his first professional defeat - an memorable fight with Callum Smith in last winter - to claim a 20th pro success.
Various analysts felt Parker, 31, should have been awarded the victory but the contender suffered the second setback of his 28-bout career.
The Champion Secures Triumph in Uneventful Match
Buatsi's progress has plateaued in the past few years through promotional disputes and long spells of lack of fights.
Once tipped as the rising talent of the British fight scene, he now finds himself trying to realize his potential - maybe in what appears to be a final roll of the dice - under recent support.
He opened tentatively, with the two boxers willing to overcommit in a cagey initial rounds.
The challenger, whose single earlier setback came at super middleweight against John Ryder in 2022 after suffering a hand injury during the bout, was making just his second bout at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, making life awkward for the favorite, who worked behind a solid defense to narrowly win the more effective rounds.
The crowd's patience diminished because of frequent holding, with the challenger going down several times during grappling.
Parker closed well, but multiple periods were hard to judge. Although, ex-champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
The victor progresses, but with the caliber of heavy hitter Benavidez, and Eastern European fighter Bivol leading the category, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Homage Fuels Local Rivalry Fight
In the co-main event, Lyndon Arthur beat Rea by close verdict in a excellent all-Manchester contest to win the European light-heavyweight belt.
The arena fell silent for a extremely emotional memorial prior to the bout as a bell ceremony tolled in memory of local hero Hatton, who died at age 46 in September.
It was the initial significant broadcast fight night in the location since Hatton's death. As the concluding sound disappeared, the stillness transitioned to a chant of "only one Hatton".
The fighting inside the ropes equaled the feeling. The eventual winner was floored by a powerful punch squarely on the jaw in the second round, standing uncertainly to his position on the referee's count.
But the traditional red equipment of Arthur soon pressed ahead again. From the other corner, the opponent - in competitive blue - was damaged soon, significant bruising forming under his face as the duo exchanged powerful shots.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with effective uppercuts as the intensity hardly diminished over the full distance.
Arthur barely secured the verdict with scoring tallies of draw, close margin and 115-112, but the two athletes were persistent and courageous, all the qualities their inspiration Hatton stood for.
