British light-heavyweight Buatsi earned a win yet underwhelming start to life under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output appeared to earn him a split decision in a tight ten-round fight at the boxing arena.
But Parker had his moments, landing some telling individual punches in a match where the styles failed to mesh, with excessive holding disrupting the fight.
The officials judged it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my best showing but how do champions respond? They prevail," the victor said in the arena as he was faced disapproval from the audience.
The Londoner bounced back after his maiden career setback - an memorable fight with his previous opponent in February - to claim a 20th career victory.
Various analysts felt Parker, thirty-one, merited the decision but the British boxer endured the second setback of his 28-fight professional journey.
The Champion Secures Triumph in Slow Encounter
Buatsi's progress has plateaued in recent times through management issues and considerable time of inactivity.
Earlier forecast as the future of British boxing, he now finds himself trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under fresh management.
He started carefully, with neither fighter prepared to be aggressive in a cagey initial rounds.
The challenger, whose single earlier setback came at super middleweight against his former opponent in 2022 after damaging his hand during the bout, was competing in only his second appearance at light-heavyweight.
By the middle rounds, the underdog had made it competitive, creating difficulties for the favorite, who operated with a protective stance to edge the better stanzas.
The audience's tolerance decreased because of frequent holding, with the challenger slipping to the canvas various instances during close exchanges.
Parker finished the stronger, but several stanzas were difficult to score. Although, ex-champion the boxing analyst - commentating on Dazn - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
Buatsi advances, but with the caliber of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Hatton Homage Fuels Local Rivalry Fight
In the co-main event, Lyndon Arthur defeated Rea by divided decision in a excellent local rivalry fight to win the European light-heavyweight belt.
The arena became quiet for a profoundly moving homage prior to the bout as a bell ceremony sounded in remembrance of local hero Hatton, who succumbed 46 years old in last month.
It was the first major televised fight night in the city since the passing of Hatton. As the final chime disappeared, the quiet became a shout of "there's only one Hatton".
The competition within the ring reflected the emotion. The eventual winner was sent to the canvas by a significant blow flush on the face in the early round, getting up unsteadily to his position on the count of eight.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in competitive blue - was marked up soon, noticeable damage developing under his eye as the fighters traded punishing blows.
Rea, twenty-seven, connected with strong blows but the champion, 34, fought fire with fire with stinging uppercuts as the pace seldom decreased over the full distance.
The victor barely secured the result with scoring tallies of even score, close margin and 115-112, but the two athletes were determined and courageous, all the qualities their hero the legend stood for.
