British light heavyweight Buatsi earned a win yet disappointing beginning to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a majority decision in a competitive ten-round bout at the boxing arena.
But the challenger landed significant shots, landing some telling individual punches in a contest where the techniques never quite clicked, with excessive holding disrupting the action.
The scoring judges judged it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my best showing but what defines champions? They succeed," the victor stated in the arena as he was met by disapproval from the audience.
The British fighter returned to winning ways after his maiden career setback - an epic battle with Callum Smith in February - to claim a 20th pro success.
Various analysts felt Parker, thirty-one, merited the win but the British boxer experienced the second defeat of his 28-match career.
The Champion Claims Victory in Uneventful Affair
The fighter's advancement has plateaued in recent years through management issues and considerable time of lack of fights.
Once tipped as the future of the British fight scene, he now is positioned trying to realize his potential - possibly in what feels like a last chance - under recent support.
He started carefully, with the two boxers prepared to take risks 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 during the bout, was making just his second bout at the higher weight class.
By the halfway stage, Parker had made it competitive, creating difficulties for the favorite, who operated with a solid defense to narrowly win the better periods.
The crowd's patience wore thin because of frequent holding, with Parker going down multiple occasions during close exchanges.
Parker finished the stronger, but multiple periods were hard to judge. Although, ex-champion the boxing analyst - commentating on Dazn - had it particularly wide for Parker, giving Buatsi just a single round.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Homage Inspires All-Manchester Fight
In the supporting bout, Arthur defeated Bradley Rea by close verdict in a excellent Manchester vs Manchester fight to secure the European light-heavyweight title.
The arena grew hushed for a extremely emotional tribute before the fight as 10 bells sounded in memory of Manchester's own Ricky Hatton, who passed away 46 years old in recently.
It was the initial significant broadcast fight night in the city since Hatton's passing. As the final chime ended, the quiet became a roar of "there's only one Ricky Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was floored by a significant blow flush on the chin in the second round, getting up unsteadily to his footing on the count of eight.
But the traditional red shorts of the fighter soon advanced again. On the opposite side, Rea - in rival City blue - was marked up quickly, significant bruising developing under his face as the pair landed hard punches.
Rea, twenty-seven, delivered effective strikes but the champion, 34, matched the intensity with powerful upward punches as the pace rarely dropped over the full distance.
Arthur narrowly won the verdict with official scores of even score, close margin and wider gap, but the two athletes were relentless and full of heart, exactly what their hero the legend represented.
