British light heavyweight Buatsi secured a victory yet underwhelming beginning to life under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a split decision in a close ten-round contest at the Manchester venue.
But the challenger had his moments, delivering effective individual punches in a contest where the techniques never quite clicked, with excessive holding marring the fight.
Two judges judged it 96-94 to Buatsi, with the remaining official a 95-95.
"It wasn't my best display but how do champions respond? They win," the victor commented in the ring as he was faced disapproval from the spectators.
The Londoner got back to winning after his initial pro loss - an thrilling contest with his previous opponent in last winter - to secure a 20th career victory.
Some ringside observers thought the challenger, thirty-one, merited the decision but the contender suffered the second setback of his 28-bout career.
Buatsi Secures Win in Dull Encounter
The fighter's advancement has plateaued in recent years through promotional disputes and long spells of lack of fights.
Once tipped as the rising talent of the British fight scene, he now finds himself trying to achieve expectations - maybe in what seems like a last chance - under fresh management.
He began cautiously, with neither fighter ready to be aggressive in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after damaging his hand in the contest, was competing in only his second bout at the higher weight class.
By the middle rounds, the underdog had made it competitive, causing problems for Buatsi, who worked behind a protective stance to narrowly win the better stanzas.
The spectators' acceptance diminished amid frequent holding, with the challenger going down multiple occasions during close exchanges.
Parker ended stronger, but several stanzas were hard to judge. However, ex-champion Carl Frampton - providing analysis for Dazn - had it strongly leaning for Parker, awarding Buatsi just one round.
The victor moves on, but with the presence of heavy hitter Benavidez, and Russian star Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Homage Motivates Manchester Derby Battle
In the co-main event, Lyndon Arthur overcame Rea by close verdict in a outstanding Manchester vs Manchester contest to capture the European light-heavyweight title.
The arena became quiet for a deeply poignant homage before the fight as ten bells tolled in honor of Manchester's own Hatton, who passed away aged 46 in last month.
It was the premier televised boxing event in the city since Hatton's passing. As the last bell ended, the stillness gave way to a roar of "there's just one Ricky Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was floored by a left hook flush on the face in the second round, rising shakily to his position on the eight count.
But the red-colored equipment of the fighter soon pressed ahead again. Across the ring, the opponent - in rival City blue - was marked up soon, significant bruising forming under his orbital area as the duo traded punishing blows.
Rea, 27, connected with strong blows but the champion, 34, fought fire with fire with stinging uppercuts as the pace hardly diminished over 12 rounds.
Arthur narrowly won the decision with official scores of 114-114, narrow lead and wider gap, but both fighters were relentless and courageous, exactly what their idol the legend embodied.
