UK light heavyweight Buatsi earned a win yet underwhelming debut to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a split decision in a competitive ten-round bout at the boxing arena.
But Parker had his moments, connecting with powerful individual punches in a fight where the techniques didn't complement each other, with constant grabbing spoiling the contest.
Two judges judged it 96-94 for to the winner, with the remaining official a 95-95.
"It wasn't my finest display but what defines champions? They prevail," the victor commented in the arena as he was greeted with disapproval from the crowd.
The Londoner got back to winning after his initial pro loss - an epic battle with his previous opponent in February - to earn a 20th pro success.
Various analysts believed Parker, 31, should have been awarded the victory but the British boxer experienced the second defeat of his 28-match professional journey.
Buatsi Earns Victory in Uneventful Affair
Buatsi's progress has plateaued in the past few years through management issues and considerable time of inactivity.
Earlier forecast as the next star of British boxing, he now finds himself trying to achieve expectations - possibly in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with neither fighter ready to overcommit in a calculated opening few rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was making just his second appearance at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, creating difficulties for Buatsi, who worked behind a protective stance to narrowly win the cleaner stanzas.
The audience's tolerance decreased during constant clinching, with Parker going down various instances during close exchanges.
The underdog finished the stronger, but several stanzas were difficult to score. However, ex-champion Carl Frampton - commentating on Dazn - had it particularly wide for Parker, scoring for Buatsi just one round.
Buatsi advances, but with the likes of hard hitter David Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still seems difficult.
Ricky Hatton Tribute Motivates Local Rivalry Contest
In the secondary fight, Arthur defeated Bradley Rea by divided decision in a terrific all-Manchester fight to win the continental title.
The venue grew hushed for a deeply poignant homage ahead of the contest as a bell ceremony tolled in honor of Manchester's own Hatton, who succumbed 46 years old in last month.
It was the initial significant broadcast match card in the location since Hatton's death. As the concluding sound disappeared, the quiet gave way to a shout of "there's just one Ricky Hatton".
The action within the ring reflected the emotion. Arthur was sent to the canvas by a significant blow directly to the chin in the second round, standing uncertainly to his position on the eight count.
But the red-colored equipment of Arthur soon advanced again. From the other corner, Rea - in competitive blue - was injured soon, heavy swelling developing under his orbital area as the fighters traded hard punches.
The challenger, 27, delivered effective strikes but Arthur, thirty-four, matched the intensity with stinging uppercuts as the action hardly diminished over twelve rounds.
Arthur narrowly won the result with scoring tallies of 114-114, close margin and clearer margin, but each competitor were relentless and courageous, exactly what their inspiration the legend stood for.
