British light heavyweight Buatsi earned a win yet underwhelming start to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a close ten-round fight at the boxing arena.
But the challenger found success, delivering effective single shots in a contest where the styles failed to mesh, with constant grabbing disrupting the fight.
Two judges scored it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my finest display but how do champions respond? They succeed," Buatsi said in the arena as he was met by disapproval from the spectators.
The British fighter bounced back after his maiden career setback - an memorable fight with his previous opponent in February - to secure a twentieth professional win.
Various analysts felt the challenger, thirty-one, should have been awarded the win but the contender suffered the second defeat of his 28-bout professional journey.
The Champion Secures Victory in Dull Affair
Buatsi's progress has plateaued in the past few years through contract problems and extended periods of inactivity.
Earlier forecast as the rising talent of British boxing, he now finds himself trying to fulfil that early promise - possibly in what appears to be a ultimate opportunity - under recent support.
He opened tentatively, with the two boxers prepared to overcommit in a calculated early stages.
Parker, whose single earlier setback came at super-middleweight against John Ryder in 2022 after suffering a hand injury mid-fight, was making just his second fight at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, causing problems for Buatsi, who worked behind a solid defense to narrowly win the cleaner stanzas.
The crowd's patience diminished during constant clinching, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog ended stronger, but multiple periods were difficult to score. Nevertheless, former world champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, scoring for Buatsi just only one stanza.
Buatsi advances, but with the likes of power puncher Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Tribute Fuels All-Manchester Fight
In the supporting bout, Lyndon Arthur beat Bradley Rea by divided decision in a outstanding local rivalry contest to capture the continental belt.
The venue became quiet for a extremely emotional homage ahead of the contest as 10 bells tolled in remembrance of Manchester's own Ricky Hatton, who succumbed 46 years old in last month.
It was the premier televised fight night in the city since Hatton's passing. As the final chime ended, the stillness transitioned to a shout of "only one Hatton".
The competition inside the ropes matched the sentiment. The eventual winner was knocked down by a left hook directly to the chin in the initial stage, getting up unsteadily to his feet on the count of eight.
But the red-colored equipment of Arthur soon came forward again. Across the ring, the opponent - in opposing blue - was injured early, significant bruising appearing under his face as the fighters landed punishing blows.
Rea, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with effective uppercuts as the action rarely dropped over 12 rounds.
The victor edged the verdict with judges scorecards of 114-114, close margin and clearer margin, but the two athletes were persistent and full of heart, exactly what their idol Hatton represented.
