UK light-heavyweight Buatsi made a winning yet unimpressive start to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a close ten-round bout at the Co-op Live Arena.
But Parker landed significant shots, delivering effective clean blows in a match where the approaches never quite clicked, with constant grabbing disrupting the fight.
The officials scored it 96-94 for to the winner, with the final judge a 95-95.
"It wasn't my best display but what defines champions? They prevail," the victor stated in the ringside as he was faced negative reactions from the crowd.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in February - to secure a 20th career victory.
Various analysts believed the challenger, 31, should have been awarded the win but the Derbyshire fighter endured the second loss of his 28-match career.
The Champion Secures Win in Slow Match
Buatsi's progress has slowed in recent years through contract problems and considerable time of lack of fights.
Once tipped as the rising talent of the British fight scene, he now finds himself trying to realize his potential - perhaps in what feels like a ultimate opportunity - under fresh management.
He began cautiously, with both competitors willing to overcommit in a calculated early stages.
Parker, whose sole prior loss came at super-middleweight against John Ryder in two years ago after damaging his hand during the bout, was competing in only his second fight at light-heavyweight.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a solid defense to barely take the better periods.
The spectators' acceptance wore thin during constant clinching, with the challenger going down multiple occasions during grappling.
Parker ended stronger, but several stanzas were difficult to score. However, ex-champion Carl Frampton - commentating on the broadcast network - had it significantly in favor for the challenger, giving Buatsi just a single round.
Buatsi moves on, but with the likes of hard hitter David Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Ricky Hatton Tribute Fuels Local Rivalry Fight
In the supporting bout, Arthur defeated Rea by divided decision in a terrific Manchester vs Manchester fight to secure the European light heavyweight title.
The stadium grew hushed for a profoundly moving tribute ahead of the contest as a bell ceremony tolled in memory of local hero Hatton, who succumbed aged 46 in last month.
It was the first major televised match card in the location since the passing of Hatton. As the final chime disappeared, the silence gave way to a chant of "only one Ricky Hatton".
The competition during the bout equaled the sentiment. The eventual winner was sent to the canvas by a left hook flush on the face in the early round, rising shakily to his position on the eight count.
But the traditional red equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in competitive blue - was damaged soon, heavy swelling developing under his orbital area as the fighters exchanged punishing blows.
Rea, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with stinging uppercuts as the action hardly diminished over twelve rounds.
The victor barely secured the verdict with scoring tallies of draw, 115-113 and 115-112, but both fighters were relentless and full of heart, all the qualities their hero the legend stood for.
