British light-heavyweight Buatsi earned a win yet unimpressive start to life under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic medal winner's work rate appeared to earn him a majority decision in a tight ten-round contest at the Manchester venue.
But Parker found success, landing some telling clean blows in a contest where the approaches never quite clicked, with constant grabbing marring the action.
Two judges scored it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my finest performance but what defines champions? They succeed," Buatsi stated in the ring as he was greeted with negative reactions from the crowd.
The British fighter got back to winning after his initial pro loss - an memorable fight with his previous opponent in last winter - to secure a 20th pro success.
Various analysts thought the challenger, thirty-one, should have been awarded the victory but the contender experienced the second setback of his 28-fight career.
Buatsi Secures Triumph in Uneventful Match
His career development has slowed in recent years through promotional disputes and considerable time of lack of fights.
Earlier forecast as the future of British boxing, he now is positioned trying to fulfil that early promise - maybe in what appears to be a last chance - under recent support.
He opened tentatively, with both competitors prepared to be aggressive in a cagey initial rounds.
The challenger, whose single earlier setback came at super-middleweight against John Ryder in two years ago after damaging his hand during the bout, was participating in his second bout at the higher weight class.
By the middle rounds, the underdog had kept it close, creating difficulties for Buatsi, who worked behind a solid defense to narrowly win the more effective periods.
The spectators' acceptance decreased during frequent holding, with the challenger slipping to the canvas several times during close exchanges.
Parker ended stronger, but several stanzas were hard to judge. Nevertheless, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, giving Buatsi just a single round.
The victor moves on, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still looks steep.
Ricky Hatton Memorial Motivates Manchester Derby Contest
In the co-main event, Arthur defeated Bradley Rea by divided decision in a outstanding local rivalry fight to win the European light-heavyweight belt.
The stadium grew hushed for a profoundly moving memorial ahead of the contest as ten bells sounded in memory of Manchester's own Hatton, who died at age 46 in recently.
It was the first major televised match card in the urban center since Hatton's death. As the final chime disappeared, the quiet gave way to a chant of "only one Hatton".
The action inside the ropes reflected the emotion. Arthur was knocked down by a significant blow flush on the jaw in the early round, rising shakily to his footing on the eight count.
But the Manchester United-red equipment of Arthur soon pressed ahead again. From the other corner, Rea - in competitive blue - was marked up soon, heavy swelling developing under his orbital area as the pair traded powerful shots.
The challenger, 27, landed power punches but Arthur, 34, fought fire with fire with stinging uppercuts as the action rarely dropped over twelve rounds.
Arthur barely secured the decision with scoring tallies of even score, close margin and clearer margin, but both fighters were determined and brave, all the qualities their idol Hatton embodied.
