British light heavyweight Buatsi earned a win yet underwhelming start to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a judges' verdict in a competitive 10-round contest at the Manchester venue.
But Parker had his moments, landing some telling clean blows in a contest where the styles never quite clicked, with constant grabbing disrupting the action.
The officials judged it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my finest performance but how do champions respond? They prevail," the victor stated in the ringside as he was met by boos from the crowd.
The Londoner bounced back after his initial pro loss - an epic battle with his previous opponent in February - to earn a 20th career victory.
Various analysts believed Parker, 31, deserved the win but the contender endured the second setback of his 28-match professional journey.
The Champion Secures Victory in Uneventful Affair
The fighter's advancement has slowed in the past few years through promotional disputes and long spells of inactivity.
Previously predicted as the rising talent of UK boxing, he now stands trying to realize his potential - possibly 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 calculated early stages.
The challenger, whose single earlier setback came at super middleweight against John Ryder in 2022 after damaging his hand in the contest, was participating in his second bout at light heavyweight.
By the middle rounds, the underdog had kept it close, making life awkward for the favorite, who worked behind a solid defense to narrowly win the cleaner periods.
The spectators' acceptance wore thin because of frequent holding, with the challenger falling to the floor various instances during clinches.
The underdog closed well, but several stanzas were challenging to assess. Nevertheless, previous titleholder Carl Frampton - working with the broadcast network - had it particularly wide for Parker, scoring for Buatsi just one round.
Buatsi progresses, but with the presence of heavy hitter David Benavidez, and Russian champion Dmitry Bivol ruling the division, the journey to titles - based on this performance - still looks steep.
Hatton Homage Fuels All-Manchester Contest
In the co-main event, Arthur overcame Rea by close verdict in a outstanding Manchester vs Manchester contest to win the European light-heavyweight championship.
The arena grew hushed for a deeply poignant memorial ahead of the contest as a bell ceremony rang in honor of local hero Ricky Hatton, who passed away at age 46 in September.
It was the premier televised match card in the urban center since Hatton's death. As the last bell faded, the quiet gave way to a roar of "there's just one Hatton".
The competition inside the ropes reflected the emotion. Arthur was sent to the canvas by a significant blow directly to the chin in the second round, rising shakily to his position on the eight count.
But the red-colored shorts of Arthur soon came forward again. Across the ring, the opponent - in rival City blue - was injured quickly, heavy swelling forming under his orbital area as the duo landed powerful shots.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with stinging uppercuts as the intensity hardly diminished over the full distance.
The victor barely secured the decision with official scores of draw, 115-113 and clearer margin, but each competitor were determined and brave, everything their idol Hatton stood for.
