UK light heavyweight Buatsi made a winning yet unimpressive beginning to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a majority decision in a tight 10-round fight at the Manchester venue.
But Parker found success, landing some telling clean blows in a fight where the approaches failed to mesh, with constant grabbing disrupting the fight.
The officials had it 96-94 to the winner, with the third a 95-95.
"It wasn't my greatest display but how do champions respond? They succeed," the victor stated in the arena as he was greeted with disapproval from the crowd.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in February - to earn a 20th pro success.
Various analysts thought Parker, thirty-one, merited the decision but the Derbyshire fighter endured the second defeat of his 28-match career.
Buatsi Earns Triumph in Slow Match
His career development has stalled in recent years through contract problems and long spells of inactivity.
Once tipped as the rising talent of British boxing, he now is positioned trying to achieve expectations - possibly in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with the two boxers ready to take risks in a tentative early stages.
Parker, whose only previous defeat came at super middleweight against his former opponent in two years ago after suffering a hand injury in the contest, was competing in only his second appearance at light-heavyweight.
By the halfway stage, Parker had kept it close, creating difficulties for Buatsi, who utilized a tight guard to barely take the more effective periods.
The spectators' acceptance wore thin amid constant clinching, with the challenger falling to the floor various instances during grappling.
Parker closed well, but multiple periods were difficult to score. Although, previous titleholder the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, awarding Buatsi just a single round.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - based on this performance - still seems difficult.
Ricky Hatton Tribute Fuels Local Rivalry Fight
In the co-main event, Lyndon Arthur beat Rea by close verdict in a outstanding all-Manchester contest to win the continental championship.
The venue became quiet for a extremely emotional homage ahead of the contest as ten bells sounded in honor of local hero Hatton, who passed away aged 46 in recently.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the concluding sound faded, the quiet gave way to a shout of "there's just one Hatton".
The fighting within the ring equaled the emotion. The eventual winner was floored by a powerful punch squarely on the jaw in the initial stage, getting up unsteadily to his footing on the count of eight.
But the traditional red attire of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was injured early, significant bruising forming under his eye as the pair exchanged powerful shots.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, fought fire with fire with powerful upward punches as the action seldom decreased over the full distance.
The victor barely secured the decision with judges scorecards of draw, 115-113 and wider gap, but the two athletes were relentless and brave, all the qualities their hero the legend represented.
