British light-heavyweight Buatsi made a winning yet disappointing debut to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a tight 10-round fight at the boxing arena.
But Parker found success, connecting with powerful individual punches in a match where the techniques didn't complement each other, with frequent clinching marring the fight.
Two judges had it 96-94 for to the winner, with the remaining official a even score.
"It wasn't my finest performance but how do champions respond? They succeed," Buatsi commented in the arena as he was met by boos from the crowd.
The British fighter bounced back after his first professional defeat - an epic battle with his previous opponent in February - to secure a 20th pro success.
Several boxing experts felt Parker, thirty-one, deserved the victory but the British boxer experienced the second setback of his 28-fight professional journey.
The Champion Earns Victory in Uneventful Affair
His career development has plateaued in recent years through promotional disputes and extended periods of lack of fights.
Previously predicted as the rising talent of UK boxing, he now is positioned trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under recent support.
He began cautiously, with the two boxers prepared to be aggressive in a cagey opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in 2022 after breaking his hand in the contest, was making just his second fight at light heavyweight.
By the halfway stage, Parker had made it competitive, causing problems for the favorite, who worked behind a tight guard to edge the better stanzas.
The spectators' acceptance decreased because of frequent holding, with the challenger slipping to the canvas various instances during clinches.
The underdog closed well, but multiple periods were challenging to assess. However, previous titleholder Carl Frampton - providing analysis for Dazn - had it particularly wide for Parker, giving Buatsi just a single round.
The victor advances, but with the caliber of power puncher Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the journey to titles - on this evidence - still looks steep.
Hatton Tribute Inspires Local Rivalry Fight
In the secondary fight, Arthur overcame Rea by divided decision in a terrific Manchester vs Manchester fight to capture the continental belt.
The venue fell silent for a extremely emotional tribute prior to the bout as a bell ceremony tolled in remembrance of Manchester's own Hatton, who passed away at age 46 in September.
It was the initial significant broadcast boxing event in the location since Hatton's death. As the last bell disappeared, the quiet became a roar of "there's just one Hatton".
The fighting inside the ropes matched the emotion. Arthur was sent to the canvas by a significant blow squarely on the face in the early round, standing uncertainly to his footing on the referee's count.
But the Manchester United-red shorts of Arthur soon pressed ahead again. From the other corner, Rea - in competitive blue - was damaged soon, heavy swelling appearing under his face as the pair exchanged hard punches.
Rea, twenty-seven, landed power punches but Arthur, 34, matched the intensity with stinging uppercuts as the intensity seldom decreased over twelve rounds.
Arthur narrowly won the result with judges scorecards of draw, close margin and clearer margin, but both fighters were persistent and brave, exactly what their hero the legend stood for.
