British light heavyweight Buatsi made a winning yet unimpressive debut to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a close 10-round contest at the Co-op Live Arena.
But Parker had his moments, connecting with powerful individual punches in a match where the approaches failed to mesh, with frequent clinching marring the action.
The officials had it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my greatest showing but what defines champions? They succeed," the victor stated in the ring as he was met by boos from the audience.
The Londoner returned to winning ways after his first professional defeat - an epic battle with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers thought the challenger, thirty-one, should have been awarded the decision but the contender experienced the second setback of his 28-bout career.
Buatsi Secures Triumph in Uneventful Affair
The fighter's advancement has stalled in the past few years through contract problems and long spells of inactivity.
Once tipped as the next star of UK boxing, he now stands trying to realize his potential - possibly in what seems like a last chance - under new promotional backing.
He opened tentatively, with the two boxers ready to take risks in a cagey initial rounds.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was participating in his second appearance at the higher weight class.
By the fight's midpoint, Parker had made it competitive, creating difficulties for the favorite, who utilized a protective stance to barely take the better rounds.
The audience's tolerance diminished because of regular grabbing, with Parker falling to the floor several times during close exchanges.
Parker closed well, but multiple periods were difficult to score. However, former world champion Carl Frampton - working with Dazn - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
Buatsi advances, but with the presence of heavy hitter Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the road to world glory - on this evidence - still seems difficult.
Hatton Homage Motivates Manchester Derby Contest
In the secondary fight, Lyndon Arthur defeated Rea by close verdict in a excellent Manchester vs Manchester fight to secure the continental title.
The stadium fell silent for a extremely emotional tribute prior to the bout as a bell ceremony sounded in honor of local hero Ricky Hatton, who died at age 46 in September.
It was the premier televised fight night in the urban center since Hatton's passing. As the last bell ended, the silence gave way to a roar of "only one Ricky Hatton".
The competition within the ring equaled the emotion. The eventual winner was floored by a significant blow flush on the jaw in the initial stage, rising shakily to his feet on the referee's count.
But the Manchester United-red equipment of the fighter soon came forward again. Across the ring, the opponent - in rival City blue - was marked up early, heavy swelling forming under his eye as the pair traded powerful shots.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, fought fire with fire with effective uppercuts as the pace hardly diminished over the full distance.
Arthur barely secured the decision with official scores of 114-114, close margin and wider gap, but both fighters were persistent and full of heart, everything their inspiration the legend represented.
