British light heavyweight Buatsi earned a win yet disappointing debut to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a judges' verdict in a competitive ten-round contest at the Co-op Live Arena.
But Parker landed significant shots, landing some telling clean blows in a contest where the techniques failed to mesh, with excessive holding disrupting the action.
The officials scored it 96-94 to the winner, with the final judge a even score.
"It wasn't my greatest performance but what do champions do? They win," the victor stated in the arena as he was greeted with negative reactions from the crowd.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in February - to earn a 20th career victory.
Several boxing experts thought the challenger, thirty-one, deserved the decision but the British boxer endured the second setback of his 28-fight professional journey.
Buatsi Claims Win in Uneventful Encounter
The fighter's advancement has stalled in recent years through contract problems and extended periods of inactivity.
Once tipped as the rising talent of UK boxing, he now stands trying to achieve expectations - possibly in what seems like a ultimate opportunity - under new promotional backing.
He opened tentatively, with neither fighter prepared to overcommit in a cagey opening few rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in 2022 after breaking his hand mid-fight, was participating in his second fight at the higher weight class.
By the fight's midpoint, Parker had kept it close, making life awkward for the favorite, who worked behind a tight guard to narrowly win the better periods.
The audience's tolerance decreased because of regular grabbing, with the challenger falling to the floor multiple occasions during clinches.
The underdog ended stronger, but many rounds were hard to judge. However, ex-champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for Parker, giving Buatsi just a single round.
Buatsi progresses, but with the likes of hard hitter Benavidez, and Eastern European fighter Bivol ruling the division, the road to world glory - judging by this showing - still appears challenging.
Hatton Tribute Inspires Manchester Derby Fight
In the co-main event, Lyndon Arthur beat Rea by split-decision in a excellent local rivalry fight to secure the European light-heavyweight title.
The stadium grew hushed for a deeply poignant homage before the fight as ten bells tolled in honor of local hero Hatton, who passed away at age 46 in last month.
It was the initial significant broadcast boxing event in the urban center since Hatton's passing. As the final chime ended, the stillness gave way to a chant of "there's only one Hatton".
The competition during the bout equaled the feeling. The eventual winner was sent to the canvas by a significant blow directly to the chin in the second round, getting up unsteadily to his footing on the count of eight.
But the red-colored attire of the fighter soon came forward again. From the other corner, the opponent - in rival City blue - was marked up soon, heavy swelling developing under his eye as the duo exchanged hard punches.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with effective uppercuts as the intensity rarely dropped over twelve rounds.
Arthur narrowly won the result with official scores of draw, narrow lead and wider gap, but the two athletes were persistent and full of heart, exactly what their idol the legend embodied.
