British light heavyweight Buatsi made a winning yet disappointing debut to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a majority decision in a tight ten-round fight at the Co-op Live Arena.
But Parker had his moments, delivering effective single shots in a contest where the styles didn't complement each other, with frequent clinching disrupting the contest.
The officials scored it 96-94 for to the winner, with the final judge a 95-95.
"It wasn't my finest display but what do champions do? They prevail," the victor said in the ring as he was greeted with disapproval from the audience.
The British fighter returned to winning ways after his first professional defeat - an thrilling contest with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers believed Parker, thirty-one, should have been awarded the win but the contender suffered the second setback of his 28-fight career.
Buatsi Earns Victory in Slow Affair
The fighter's advancement has slowed in the past few years through management issues and extended periods of lack of fights.
Previously predicted as the rising talent of the British fight scene, he now is positioned trying to realize his potential - perhaps in what seems like a last chance - under recent support.
He started carefully, with the two boxers prepared to take risks in a calculated opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after suffering a hand injury in the contest, was making just his second bout at the higher weight class.
By the halfway stage, Parker had stayed in contention, creating difficulties for the favorite, who operated with a solid defense to barely take the more effective stanzas.
The spectators' acceptance diminished during regular grabbing, with the challenger going down various instances during close exchanges.
The underdog ended stronger, but multiple periods were difficult to score. Although, ex-champion the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just one round.
Buatsi moves on, but with the presence of heavy hitter David Benavidez, and Russian champion Dmitry Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Hatton Homage Inspires Local Rivalry Battle
In the supporting bout, Arthur overcame Rea by split-decision in a terrific local rivalry battle to win the European light-heavyweight title.
The venue became quiet for a profoundly moving memorial prior to the bout as ten bells rang in remembrance of the city's native Hatton, who succumbed at age 46 in September.
It was the premier televised boxing event in the city since Hatton's passing. As the final chime disappeared, the silence transitioned to a shout of "only one Ricky Hatton".
The action inside the ropes reflected the sentiment. The eventual winner was sent to the canvas by a significant blow directly to the chin in the second round, rising shakily to his feet on the eight count.
But the red-colored attire of Arthur soon came forward again. On the opposite side, the opponent - in opposing blue - was marked up quickly, significant bruising forming under his eye as the pair landed powerful shots.
Rea, twenty-seven, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the action hardly diminished over twelve rounds.
The victor barely secured the result with official scores of 114-114, close margin and wider gap, but each competitor were persistent and brave, all the qualities their hero the legend embodied.
