UK light heavyweight Buatsi secured a victory yet disappointing beginning to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's work rate seemingly secured him a majority decision in a competitive 10-round contest at the boxing arena.
But Parker found success, connecting with powerful clean blows in a fight where the techniques never quite clicked, with excessive holding spoiling the action.
Two judges judged it 96-94 in favor to the winner, with the remaining official a 95-95.
"It wasn't my greatest display but what do champions do? They prevail," the victor stated in the arena as he was faced negative reactions from the spectators.
The British fighter returned to winning ways after his first professional defeat - an epic battle with his previous opponent in last winter - to secure a 20th pro success.
Several boxing experts thought Parker, thirty-one, merited the decision but the contender suffered the second defeat of his 28-fight professional journey.
The Champion Secures Victory in Slow Match
The fighter's advancement has slowed in the past few years through contract problems and long spells of lack of fights.
Previously predicted as the future of British boxing, he now stands trying to fulfil that early promise - possibly in what feels like a last chance - under new promotional backing.
He started carefully, with both competitors ready to take risks in a calculated initial rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in 2022 after suffering a hand injury mid-fight, was participating in his second appearance at the higher weight class.
By the middle rounds, the underdog had made it competitive, causing problems for the favorite, who operated with a protective stance to narrowly win the better rounds.
The spectators' acceptance diminished during frequent holding, with the challenger slipping to the canvas multiple occasions during close exchanges.
The underdog ended stronger, but multiple periods were challenging to assess. Although, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for Parker, awarding Buatsi just one round.
Buatsi moves on, but with the likes of power puncher Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still seems difficult.
Hatton Memorial Inspires Local Rivalry Battle
In the co-main event, Lyndon Arthur beat Rea by split-decision in a outstanding Manchester vs Manchester battle to capture the European light heavyweight belt.
The stadium grew hushed for a extremely emotional memorial ahead of the contest as 10 bells sounded in memory of local hero Hatton, who died at age 46 in last month.
It was the first major televised boxing event in the city since Hatton's passing. As the last bell ended, the silence transitioned to a roar of "there's just one Ricky Hatton".
The fighting within the ring equaled the emotion. Arthur was knocked down by a significant blow flush on the face in the second round, rising shakily to his feet on the referee's count.
But the red-colored equipment of the fighter soon came forward again. Across the ring, Rea - in rival City blue - was injured quickly, noticeable damage developing under his face as the pair landed hard punches.
Rea, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with effective uppercuts as the intensity rarely dropped over the full distance.
Arthur narrowly won the verdict with judges scorecards of 114-114, 115-113 and clearer margin, but each competitor were determined and courageous, all the qualities their hero Hatton represented.
