UK light heavyweight Buatsi made a winning yet disappointing debut to life under fresh promotional backing with a decision win over Zach Parker in Manchester.
The Olympic medal winner's work rate appeared to earn him a split decision in a close 10-round bout at the boxing arena.
But Parker had his moments, connecting with powerful clean blows in a fight where the techniques didn't complement each other, with excessive holding marring the contest.
The officials had it 96-94 in favor to Buatsi, with the third a even score.
"It wasn't my best performance but what do champions do? They win," the victor stated in the ringside as he was met by boos from the spectators.
The Londoner got back to winning after his first professional defeat - an thrilling contest with his previous opponent in February - to secure a twentieth professional win.
Several boxing experts felt the challenger, thirty-one, merited the win but the Derbyshire fighter experienced the second setback of his 28-bout professional journey.
Buatsi Secures Win in Dull Affair
The fighter's advancement has slowed in the past few years through promotional disputes and considerable time of lack of fights.
Earlier forecast as the next star of UK boxing, he now stands trying to realize his potential - maybe in what appears to be a ultimate opportunity - under new promotional backing.
He began cautiously, with the two boxers prepared to be aggressive in a calculated initial rounds.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in two years ago after damaging his hand mid-fight, was competing in only his second bout at the higher weight class.
By the middle rounds, Parker had kept it close, causing problems for Buatsi, who worked behind a solid defense to edge the cleaner rounds.
The crowd's patience decreased because of frequent holding, with the challenger falling to the floor several times during clinches.
The underdog finished the stronger, but multiple periods were hard to judge. Although, previous titleholder Carl Frampton - working with Dazn - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
Buatsi advances, but with the caliber of power puncher Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the path to championship success - on this evidence - still appears challenging.
Hatton Memorial Motivates Manchester Derby Contest
In the co-main event, Lyndon Arthur overcame Bradley Rea by divided decision in a outstanding Manchester vs Manchester fight to win the European light-heavyweight title.
The venue became quiet for a profoundly moving tribute prior to the bout as a bell ceremony rang in honor of local hero Hatton, who died 46 years old in recently.
It was the initial significant broadcast match card in the urban center since Hatton's passing. As the concluding sound ended, the stillness became a roar of "there's just one Hatton".
The competition inside the ropes matched the feeling. The eventual winner was knocked down by a significant blow flush on the jaw in the second round, getting up unsteadily to his position on the referee's count.
But the Manchester United-red attire of Arthur soon pressed ahead again. Across the ring, Rea - in competitive blue - was marked up soon, noticeable damage forming under his orbital area as the pair traded powerful shots.
Rea, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the action hardly diminished over twelve rounds.
Arthur narrowly won the decision with scoring tallies of even score, narrow lead and 115-112, but the two athletes were relentless and brave, everything their idol the legend embodied.
