British light-heavyweight Buatsi made a winning yet underwhelming start to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a split decision in a close ten-round fight at the boxing arena.
But Parker had his moments, delivering effective individual punches in a match where the techniques failed to mesh, with frequent clinching marring the action.
The scoring judges judged it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my greatest display but what defines champions? They succeed," Buatsi commented in the ringside as he was faced negative reactions from the spectators.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Various analysts felt Parker, thirty-one, deserved the decision but the Derbyshire fighter suffered the second loss of his 28-bout career.
The Champion Claims Win in Uneventful Match
The fighter's advancement has slowed in recent times through management issues and considerable time of inactivity.
Earlier forecast as the rising talent of UK boxing, he now finds himself trying to fulfil that early promise - perhaps in what feels like a ultimate opportunity - under new promotional backing.
He opened tentatively, with the two boxers willing to take risks in a cagey early stages.
The challenger, whose only previous defeat came at super middleweight against his former opponent in two years ago after damaging his hand in the contest, was participating in his second appearance at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, making life awkward for the favorite, who worked behind a tight guard to edge the better periods.
The spectators' acceptance wore thin because of regular grabbing, with the challenger going down multiple occasions during close exchanges.
The underdog ended stronger, but many rounds were hard to judge. Nevertheless, previous titleholder Carl Frampton - commentating on Dazn - had it strongly leaning for Parker, giving Buatsi just only one stanza.
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.
Hatton Memorial Motivates Manchester Derby Fight
In the co-main event, Arthur overcame Rea by divided decision in a outstanding local rivalry contest to capture the continental title.
The venue became quiet for a extremely emotional tribute ahead of the contest as ten bells rang in honor of the city's native Hatton, who died 46 years old in recently.
It was the first major televised boxing event in the urban center since Hatton's passing. As the final chime faded, the silence became a shout of "there's just one Hatton".
The competition during the bout equaled the feeling. Arthur was sent to the canvas by a powerful punch squarely on the jaw in the second round, getting up unsteadily to his footing on the eight count.
But the red-colored shorts of the fighter soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was marked up early, noticeable damage forming under his orbital area as the fighters exchanged hard punches.
Rea, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity seldom decreased over 12 rounds.
The victor narrowly won the result with scoring tallies of even score, 115-113 and 115-112, but the two athletes were determined and courageous, exactly what their inspiration Hatton represented.
