British light-heavyweight Buatsi made a winning yet underwhelming start to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a split decision in a competitive ten-round bout at the Manchester venue.
But Parker had his moments, delivering effective individual punches in a match where the styles never quite clicked, with excessive holding disrupting the contest.
The scoring judges scored it 96-94 for to the winner, with the final judge a 95-95.
"It wasn't my best showing but how do champions respond? They prevail," Buatsi commented in the ring as he was met by negative reactions from the spectators.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in February - to secure a 20th career victory.
Some ringside observers thought Parker, thirty-one, deserved the victory but the contender endured the second defeat of his 28-bout career.
Buatsi Claims Victory in Uneventful Encounter
His career development has plateaued in recent times through contract problems and extended periods of lack of fights.
Once tipped as the future of British boxing, he now is positioned trying to achieve expectations - possibly in what seems like a ultimate opportunity - under recent support.
He started carefully, with both competitors willing to take risks in a calculated opening few rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after breaking his hand during the bout, was participating in his second appearance at the higher weight class.
By the fight's midpoint, the underdog had kept it close, creating difficulties for the favorite, who worked behind a protective stance to edge the more effective stanzas.
The spectators' acceptance decreased amid constant clinching, with Parker slipping to the canvas several times during close exchanges.
Parker finished the stronger, but several stanzas were difficult to score. However, ex-champion the boxing analyst - providing analysis for Dazn - had it particularly wide for Parker, awarding Buatsi just one round.
Buatsi moves on, but with the caliber of power puncher Benavidez, and Russian star Dmitry Bivol ruling the division, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Memorial Motivates All-Manchester Contest
In the supporting bout, Arthur overcame Bradley Rea by divided decision in a terrific all-Manchester contest to win the European light-heavyweight title.
The stadium fell silent for a profoundly moving memorial prior to the bout as 10 bells sounded in honor of Manchester's own Ricky Hatton, who died at age 46 in recently.
It was the first major televised fight night in the urban center since the passing of Hatton. As the concluding sound disappeared, the quiet gave way to a chant of "there's just one Hatton".
The action within the ring reflected the sentiment. Arthur was sent to the canvas by a left hook directly to the chin in the second round, standing uncertainly to his feet on the eight count.
But the red-colored equipment of Arthur soon advanced again. On the opposite side, the opponent - in rival City blue - was injured quickly, heavy swelling appearing under his eye as the duo exchanged powerful shots.
The challenger, 27, delivered effective strikes but Arthur, 34, responded in kind with stinging uppercuts as the intensity rarely dropped over 12 rounds.
The victor barely secured the verdict with judges scorecards of even score, close margin and 115-112, but the two athletes were persistent and full of heart, all the qualities their inspiration the legend stood for.
