UK light heavyweight Buatsi earned a win yet underwhelming beginning to life under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But Parker landed significant shots, landing some telling clean blows in a match where the techniques didn't complement each other, with frequent clinching marring the action.
Two judges had it 96-94 in favor to the winner, with the remaining official a 95-95.
"It wasn't my greatest performance but what do champions do? They prevail," Buatsi commented in the ring as he was greeted with boos from the spectators.
The British fighter returned to winning ways after his maiden career setback - an thrilling contest with Callum Smith in February - to claim a 20th pro success.
Some ringside observers thought Parker, 31, merited the win but the Derbyshire fighter suffered the second setback of his 28-fight professional journey.
The Champion Secures Victory in Dull Encounter
His career development has stalled in recent times through management issues and long spells of inactivity.
Previously predicted as the future of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a last chance - under new promotional backing.
He opened tentatively, with both competitors ready to be aggressive in a calculated early stages.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after breaking his hand during the bout, was making just his second appearance at light heavyweight.
By the halfway stage, Parker had made it competitive, causing problems for Buatsi, who utilized a protective stance to narrowly win the better stanzas.
The audience's tolerance wore thin because of constant clinching, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog ended stronger, but several stanzas were difficult to score. Although, ex-champion the boxing analyst - working with the broadcast network - had it particularly wide for Parker, giving Buatsi just only one stanza.
The victor progresses, but with the caliber of hard hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the path to championship success - judging by this showing - still seems difficult.
Hatton Memorial Inspires Local Rivalry Fight
In the supporting bout, Arthur defeated Rea by split-decision in a excellent local rivalry contest to win the continental title.
The arena fell silent for a extremely emotional tribute prior to the bout as 10 bells tolled in remembrance of the city's native Hatton, who succumbed at age 46 in recently.
It was the first major televised boxing event in the urban center since Hatton's death. As the last bell disappeared, the quiet became a roar of "there's just one Ricky Hatton".
The action within the ring reflected the sentiment. The eventual winner was sent to the canvas by a powerful punch squarely on the face in the early round, rising shakily to his feet on the eight count.
But the traditional red attire of Arthur soon pressed ahead again. On the opposite side, the opponent - in rival City blue - was injured soon, noticeable damage forming under his eye as the duo landed hard punches.
Rea, 27, connected with strong blows but the champion, 34, fought fire with fire with effective uppercuts as the intensity hardly diminished over 12 rounds.
The victor narrowly won the decision with official scores of draw, narrow lead and wider gap, but the two athletes were persistent and brave, everything their hero the legend stood for.
