British light heavyweight Buatsi made a winning yet underwhelming beginning to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a split decision in a competitive ten-round contest at the boxing arena.
But Parker found success, landing some telling individual punches in a fight where the techniques never quite clicked, with constant grabbing spoiling the fight.
The scoring judges scored it 96-94 to the winner, with the remaining official a 95-95.
"It wasn't my best performance but what do champions do? They succeed," the victor commented in the arena as he was faced negative reactions from the crowd.
The British fighter returned to winning ways after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Several boxing experts thought Parker, 31, should have been awarded the win but the contender experienced the second loss of his 28-match professional journey.
The Champion Claims Victory in Slow Encounter
The fighter's advancement has slowed in the past few years through promotional disputes and extended periods of inactivity.
Previously predicted as the future of British boxing, he now finds himself trying to fulfil that early promise - perhaps in what feels like a ultimate opportunity - under recent support.
He began cautiously, with both competitors ready to be aggressive in a tentative initial rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was making just his second fight at light-heavyweight.
By the middle rounds, Parker had stayed in contention, causing problems for the favorite, who worked behind a solid defense to edge the more effective rounds.
The crowd's patience diminished amid constant clinching, with the challenger going down several times during grappling.
Parker finished the stronger, but several stanzas were difficult to score. However, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, awarding Buatsi just only one stanza.
Buatsi moves on, but with the caliber of power puncher David Benavidez, and Russian star Bivol leading the category, the journey to titles - based on this performance - still seems difficult.
Hatton Memorial Fuels Manchester Derby Battle
In the secondary fight, Lyndon Arthur defeated Bradley Rea by close verdict in a excellent local rivalry fight to win the continental belt.
The stadium became quiet for a profoundly moving homage prior to the bout as a bell ceremony tolled in memory of local hero Hatton, who passed away aged 46 in recently.
It was the initial significant broadcast match card in the city since Hatton's passing. As the final chime ended, the quiet gave way to a chant of "only one Ricky Hatton".
The action during the bout reflected the feeling. Arthur was knocked down by a powerful punch directly to the jaw in the second round, getting up unsteadily to his position on the referee's count.
But the red-colored equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in rival City blue - was marked up soon, significant bruising forming under his face as the fighters traded powerful shots.
Rea, twenty-seven, delivered effective strikes but the champion, 34, fought fire with fire with effective uppercuts as the action seldom decreased over 12 rounds.
The victor barely secured the result with judges scorecards of 114-114, narrow lead and 115-112, but both fighters were relentless and full of heart, exactly what their inspiration the legend represented.
