British light-heavyweight Buatsi secured a victory yet underwhelming debut to his career under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level seemingly secured him a judges' verdict in a tight ten-round bout at the boxing arena.
But Parker found success, connecting with powerful single shots in a contest where the approaches didn't complement each other, with constant grabbing spoiling the fight.
The officials had it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what defines champions? They win," the victor stated in the arena as he was faced negative reactions from the audience.
The British fighter returned to winning ways after his maiden career setback - an epic battle with his previous opponent in last winter - to earn a 20th career victory.
Several boxing experts felt the challenger, thirty-one, should have been awarded the decision but the contender experienced the second defeat of his 28-match career.
Buatsi Earns Victory in Dull Match
The fighter's advancement has stalled in the past few years through contract problems and long spells of inactivity.
Previously predicted as the next star of British boxing, he now finds himself trying to achieve expectations - possibly in what appears to be a ultimate opportunity - under new promotional backing.
He started carefully, with neither fighter willing to take risks in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against his former opponent in two years ago after breaking his hand in the contest, was making just his second appearance at light heavyweight.
By the middle rounds, the underdog had stayed in contention, causing problems for the favorite, who worked behind a protective stance to edge the better stanzas.
The crowd's patience wore thin during regular grabbing, with the challenger going down several times during clinches.
Parker ended stronger, but several stanzas were hard to judge. Although, former world champion Carl Frampton - commentating on the broadcast network - had it strongly leaning for Parker, awarding Buatsi just one round.
Buatsi moves on, but with the caliber of hard hitter Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - based on this performance - still seems difficult.
Hatton Memorial Fuels Local Rivalry Contest
In the co-main event, Lyndon Arthur beat Bradley Rea by split-decision in a excellent local rivalry contest to win the continental title.
The stadium fell silent for a extremely emotional homage prior to the bout as 10 bells rang in remembrance of Manchester's own Ricky Hatton, who died aged 46 in September.
It was the initial significant broadcast boxing event in the location since the passing of Hatton. As the final chime faded, the quiet became a roar of "there's just one Ricky Hatton".
The competition inside the ropes equaled the emotion. The eventual winner was knocked down by a significant blow flush on the chin in the second round, getting up unsteadily to his footing on the eight count.
But the red-colored shorts of Arthur soon came forward again. On the opposite side, the opponent - in rival City blue - was marked up quickly, noticeable damage developing under his orbital area as the fighters exchanged punishing blows.
The challenger, 27, connected with strong blows but Arthur, thirty-four, responded in kind with effective uppercuts as the pace seldom decreased over twelve rounds.
Arthur narrowly won the verdict with official scores of 114-114, narrow lead and 115-112, but each competitor were relentless and brave, exactly what their hero the legend stood for.
