British light heavyweight Buatsi made a winning yet unimpressive beginning to life under new promoters with a points victory over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a split decision in a competitive ten-round contest at the Co-op Live Arena.
But Parker had his moments, delivering effective clean blows in a fight where the approaches never quite clicked, with constant grabbing marring the fight.
The officials had it 96-94 in favor to Buatsi, with the remaining official a 95-95.
"It wasn't my best showing but what defines champions? They succeed," the victor said in the ringside as he was greeted with disapproval from the audience.
The Londoner bounced back after his first professional defeat - an thrilling contest with Callum Smith in last winter - to claim a 20th pro success.
Several boxing experts felt the challenger, 31, merited the victory but the British boxer endured the second defeat of his 28-bout career.
Buatsi Claims Win in Dull Encounter
The fighter's advancement has plateaued in recent times through management issues and considerable time of inactivity.
Previously predicted as the rising talent of UK boxing, he now stands trying to fulfil that early promise - perhaps in what feels like a last chance - under fresh management.
He opened tentatively, with both competitors willing to overcommit in a calculated opening few rounds.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after breaking his hand in the contest, was competing in only his second appearance at light heavyweight.
By the halfway stage, Parker had made it competitive, causing problems for the favorite, who operated with a protective stance to narrowly win the cleaner rounds.
The audience's tolerance diminished because of frequent holding, with Parker going down several times during close exchanges.
The underdog ended stronger, but many rounds were difficult to score. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just one round.
Buatsi progresses, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the path to championship success - judging by this showing - still appears challenging.
Hatton Tribute Fuels Local Rivalry Contest
In the supporting bout, Arthur defeated Rea by close verdict in a outstanding all-Manchester battle to secure the continental title.
The stadium grew hushed for a extremely emotional memorial ahead of the contest as ten bells sounded in memory of the city's native Hatton, who died 46 years old in September.
It was the initial significant broadcast boxing event in the location since Hatton's passing. As the concluding sound faded, the stillness gave way to a chant of "there's just one Ricky Hatton".
The fighting during the bout reflected the emotion. Arthur was floored by a left hook squarely on the face in the initial stage, standing uncertainly to his footing on the referee's count.
But the traditional red equipment of the fighter soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was damaged soon, noticeable damage appearing under his face as the pair landed powerful shots.
The challenger, 27, connected with strong blows but Arthur, thirty-four, fought fire with fire with effective uppercuts as the pace seldom decreased over the full distance.
The victor narrowly won the verdict with judges scorecards of draw, close margin and clearer margin, but each competitor were persistent and courageous, everything their inspiration Hatton embodied.
