British light heavyweight Buatsi earned a win yet underwhelming beginning to life under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a judges' verdict in a competitive 10-round fight at the boxing arena.
But the challenger landed significant shots, connecting with powerful individual punches in a fight where the approaches failed to mesh, with excessive holding spoiling the contest.
The scoring judges had it 96-94 to the winner, with the final judge a even score.
"It wasn't my greatest showing but how do champions respond? They win," Buatsi said in the ring as he was met by negative reactions from the audience.
The Londoner bounced back after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Several boxing experts felt Parker, thirty-one, deserved the win but the contender suffered the second setback of his 28-bout career.
The Champion Earns Win in Dull Affair
His career development has slowed in recent times through promotional disputes and long spells of inactivity.
Previously predicted as the rising talent of the British fight scene, he now is positioned trying to realize his potential - maybe in what seems like a last chance - under recent support.
He began cautiously, with the two boxers prepared to be aggressive in a calculated initial rounds.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury during the bout, was making just his second fight at the higher weight class.
By the middle rounds, the underdog had stayed in contention, making life awkward for Buatsi, who operated with a tight guard to edge the more effective periods.
The audience's tolerance diminished amid regular grabbing, with the challenger slipping to the canvas various instances during grappling.
Parker closed well, but multiple periods were hard to judge. Although, former world champion the boxing analyst - commentating on Dazn - had it particularly wide for Parker, giving Buatsi just only one stanza.
The victor moves on, but with the caliber of power puncher Benavidez, and Eastern European fighter Bivol dominating the weight class, the path to championship success - based on this performance - still looks steep.
Ricky Hatton Memorial Motivates Local Rivalry Battle
In the supporting bout, Lyndon Arthur beat Rea by split-decision in a excellent local rivalry fight to win the European light heavyweight title.
The stadium became quiet for a extremely emotional homage before the fight as a bell ceremony tolled in honor of the city's native Ricky Hatton, who passed away aged 46 in last month.
It was the premier televised fight night in the city since the passing of Hatton. As the final chime disappeared, the stillness transitioned to a shout of "there's only one Ricky Hatton".
The action during the bout matched the sentiment. The eventual winner was floored by a powerful punch squarely on the jaw in the early round, rising shakily to his position on the eight count.
But the red-colored shorts of the fighter soon came forward again. Across the ring, the opponent - in rival City blue - was damaged early, significant bruising forming under his face as the fighters exchanged hard punches.
The challenger, twenty-seven, delivered effective strikes but Arthur, 34, fought fire with fire with stinging uppercuts as the intensity seldom decreased over the full distance.
The victor narrowly won the verdict with official scores of draw, 115-113 and clearer margin, but the two athletes were persistent and courageous, all the qualities their idol Hatton stood for.
