British light heavyweight Buatsi secured a victory yet disappointing debut to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a split decision in a competitive ten-round bout at the boxing arena.
But Parker had his moments, landing some telling individual punches in a match where the styles didn't complement each other, with excessive holding spoiling the contest.
The officials judged it 96-94 to the winner, with the final judge a 95-95.
"It wasn't my greatest performance but how do champions respond? They win," the victor stated in the ring as he was met by boos from the spectators.
The Londoner returned to winning ways after his first professional defeat - an thrilling contest with Callum Smith in February - to secure a 20th pro success.
Several boxing experts felt Parker, thirty-one, should have been awarded the decision but the contender endured the second loss of his 28-match professional journey.
Buatsi Secures Win in Dull Affair
The fighter's advancement has stalled in the past few years through contract problems and extended periods 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 recent support.
He began cautiously, with neither fighter ready to be aggressive in a calculated initial rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in two years ago after suffering a hand injury mid-fight, was participating in his second fight at the higher weight class.
By the middle rounds, the underdog had kept it close, creating difficulties for Buatsi, who utilized a solid defense to narrowly win the cleaner rounds.
The audience's tolerance decreased because of frequent holding, with Parker slipping to the canvas multiple occasions during grappling.
The underdog closed well, but many rounds were hard to judge. Nevertheless, previous titleholder Carl Frampton - commentating on the broadcast network - had it significantly in favor for Parker, giving Buatsi just one round.
The victor moves on, but with the caliber of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Tribute Fuels All-Manchester Fight
In the secondary fight, Arthur beat Rea by divided decision in a outstanding Manchester vs Manchester fight to win the European light heavyweight title.
The arena grew hushed for a deeply poignant homage before the fight as ten bells rang in remembrance of the city's native Hatton, who succumbed aged 46 in recently.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the last bell disappeared, the quiet gave way to a roar of "there's just one Hatton".
The fighting during the bout matched the feeling. Arthur was sent to the canvas by a powerful punch flush on the chin in the initial stage, getting up unsteadily to his feet on the count of eight.
But the Manchester United-red equipment of Arthur soon advanced again. From the other corner, Rea - in competitive blue - was marked up quickly, heavy swelling appearing under his eye as the pair traded punishing blows.
Rea, 27, delivered effective strikes but Arthur, 34, matched the intensity with stinging uppercuts as the action hardly diminished over 12 rounds.
The victor narrowly won the verdict with scoring tallies of draw, 115-113 and wider gap, but each competitor were determined and full of heart, all the qualities their idol Hatton stood for.
