UK light-heavyweight Buatsi made a winning yet disappointing start to life under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a competitive ten-round bout at the Co-op Live Arena.
But Parker found success, landing some telling individual punches in a fight where the approaches never quite clicked, with constant grabbing disrupting the action.
The officials scored it 96-94 for to the winner, with the final judge a 95-95 draw.
"It wasn't my greatest showing but what defines champions? They succeed," the victor stated in the arena as he was greeted with boos from the spectators.
The British fighter returned to winning ways after his initial pro loss - an memorable fight with his previous opponent in last winter - to earn a twentieth professional win.
Various analysts felt Parker, 31, deserved the decision but the British boxer experienced the second setback of his 28-fight career.
The Champion Claims Victory in Uneventful Affair
The fighter's advancement has plateaued in recent years through promotional disputes and long spells of inactivity.
Earlier forecast as the next star of British boxing, he now stands trying to realize his potential - maybe in what seems like a final roll of the dice - under new promotional backing.
He opened tentatively, with both competitors prepared to overcommit in a calculated opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in 2022 after damaging his hand in the contest, was participating in his second bout at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, causing problems for the favorite, who utilized a protective stance to barely take the better periods.
The spectators' acceptance decreased because of frequent holding, with the challenger falling to the floor several times during grappling.
Parker finished the stronger, but several stanzas were hard to judge. Nevertheless, ex-champion the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
The victor moves on, but with the caliber of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Hatton Tribute Fuels Local Rivalry Contest
In the secondary fight, Arthur beat Rea by split-decision in a excellent Manchester vs Manchester fight to secure the continental title.
The stadium became quiet for a extremely emotional homage ahead of the contest as 10 bells rang in remembrance of local hero Hatton, who passed away 46 years old in recently.
It was the first major televised match card in the location since the passing of Hatton. As the last bell faded, the quiet became a roar of "only one Hatton".
The competition during the bout matched the emotion. The eventual winner was knocked down by a powerful punch squarely on the jaw in the early round, rising shakily to his position on the eight count.
But the red-colored attire of Arthur soon came forward again. Across the ring, Rea - in competitive blue - was marked up soon, noticeable damage appearing under his eye as the duo traded punishing blows.
The challenger, twenty-seven, delivered effective strikes but the champion, thirty-four, fought fire with fire with stinging uppercuts as the intensity seldom decreased over twelve rounds.
The victor barely secured the result with official scores of even score, close margin and clearer margin, but both fighters were persistent and brave, exactly what their idol the legend embodied.
