UK light-heavyweight Buatsi made a winning yet disappointing debut to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a majority decision in a close 10-round bout at the Manchester venue.
But Parker landed significant shots, delivering effective individual punches in a contest where the techniques didn't complement each other, with excessive holding disrupting the action.
The officials had it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my best display but what do champions do? They prevail," Buatsi stated in the ring as he was greeted with disapproval from the spectators.
The British fighter returned to winning ways after his first professional defeat - an epic battle with his previous opponent in February - to earn a twentieth professional win.
Various analysts believed the challenger, thirty-one, merited the win but the contender endured the second setback of his 28-fight professional journey.
The Champion Earns Triumph in Slow Encounter
Buatsi's progress has slowed in recent years through management issues and considerable time of inactivity.
Previously predicted as the rising talent of the British fight scene, he now stands trying to fulfil that early promise - maybe in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors prepared to be aggressive in a tentative opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in two years ago after breaking his hand mid-fight, was competing in only his second fight at the higher weight class.
By the fight's midpoint, Parker had stayed in contention, causing problems for the favorite, who operated with a solid defense to barely take the cleaner periods.
The spectators' acceptance diminished because of frequent holding, with Parker falling to the floor several times during close exchanges.
Parker closed well, but many rounds were hard to judge. Although, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, awarding Buatsi just only one stanza.
Buatsi moves on, but with the likes of heavy hitter David Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - based on this performance - still looks steep.
Ricky Hatton Tribute Inspires Local Rivalry Battle
In the supporting bout, Arthur beat Bradley Rea by close verdict in a outstanding local rivalry fight to win the European light-heavyweight title.
The stadium fell silent for a deeply poignant memorial ahead of the contest as a bell ceremony sounded in memory of the city's native Hatton, who succumbed 46 years old in last month.
It was the premier televised fight night in the city since the passing of Hatton. As the last bell ended, the quiet became a chant of "only one Ricky Hatton".
The competition inside the ropes matched the sentiment. The eventual winner was sent to the canvas by a powerful punch directly to the chin in the initial stage, rising shakily to his position on the referee's count.
But the traditional red shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in opposing blue - was injured quickly, noticeable damage forming under his orbital area as the fighters traded punishing blows.
The challenger, 27, connected with strong blows but the champion, 34, fought fire with fire with stinging uppercuts as the intensity rarely dropped over twelve rounds.
Arthur narrowly won the result with judges scorecards of draw, narrow lead and wider gap, but each competitor were relentless and brave, everything their inspiration the legend represented.
