UK light-heavyweight Buatsi earned a win yet unimpressive start to life under fresh promotional backing with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a close ten-round bout at the boxing arena.
But Parker landed significant shots, landing some telling single shots in a fight where the styles didn't complement each other, with excessive holding disrupting the action.
The scoring judges scored it 96-94 for to the winner, with the final judge a even score.
"It wasn't my greatest showing but how do champions respond? They win," the victor stated in the ringside as he was faced boos from the spectators.
The Londoner returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a 20th pro success.
Various analysts felt Parker, 31, should have been awarded the win but the contender experienced the second setback of his 28-match career.
Buatsi Earns Win in Dull Encounter
Buatsi's progress has stalled in recent years through promotional disputes and long spells of inactivity.
Earlier forecast as the next star of the British fight scene, he now finds himself trying to achieve expectations - maybe in what appears to be a last chance - under new promotional backing.
He opened tentatively, with neither fighter prepared to be aggressive in a cagey initial rounds.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury mid-fight, was competing in only his second appearance at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, causing problems for the favorite, who utilized a solid defense to barely take the more effective stanzas.
The audience's tolerance wore thin because of constant clinching, with the challenger slipping to the canvas several times during grappling.
Parker finished the stronger, but several stanzas were difficult to score. Nevertheless, ex-champion the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, giving Buatsi just one round.
Buatsi moves on, but with the likes of heavy hitter David Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Homage Inspires Manchester Derby Contest
In the co-main event, Arthur defeated Bradley Rea by split-decision in a terrific local rivalry battle to capture the continental championship.
The stadium fell silent for a extremely emotional homage prior to the bout as ten bells tolled in memory of Manchester's own Ricky Hatton, who died at age 46 in September.
It was the first major televised boxing event in the location since Hatton's death. As the concluding sound faded, the quiet gave way to a chant of "there's only one Ricky Hatton".
The competition inside the ropes equaled the feeling. The eventual winner was knocked down by a left hook squarely on the jaw in the initial stage, rising shakily to his footing on the count of eight.
But the traditional red equipment of Arthur soon pressed ahead again. From the other corner, the opponent - in competitive blue - was marked up quickly, heavy swelling forming under his face as the duo exchanged hard punches.
Rea, 27, connected with strong blows but Arthur, 34, responded in kind with stinging uppercuts as the intensity rarely dropped over twelve rounds.
The victor barely secured the verdict with judges scorecards of even score, narrow lead and 115-112, but both fighters were relentless and full of heart, all the qualities their hero Hatton represented.
