British light-heavyweight Buatsi secured a victory yet disappointing beginning to life under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a majority decision in a competitive ten-round fight at the Co-op Live Arena.
But Parker had his moments, delivering effective individual punches in a fight where the approaches failed to mesh, with excessive holding marring the fight.
The scoring judges had it 96-94 in favor to the winner, with the final judge a 95-95.
"It wasn't my greatest display but what do champions do? They prevail," Buatsi stated in the ring as he was greeted with disapproval from the audience.
The British fighter bounced back after his initial pro loss - an epic battle with Callum Smith in February - to claim a 20th career victory.
Several boxing experts thought the challenger, 31, deserved the win but the Derbyshire fighter suffered the second setback of his 28-fight professional journey.
Buatsi Secures Triumph in Dull Encounter
Buatsi's progress has slowed in the past few years through management issues and considerable time of inactivity.
Previously predicted as the rising talent of British boxing, he now finds himself trying to achieve expectations - maybe in what seems like a final roll of the dice - under recent support.
He began cautiously, with both competitors willing to take risks in a calculated early stages.
Parker, whose sole prior loss came at super-middleweight against John Ryder in two years ago after suffering a hand injury in the contest, 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 better rounds.
The crowd's patience decreased amid constant clinching, with the challenger going down several times during grappling.
The underdog closed well, but multiple periods were challenging to assess. Although, former world champion Carl Frampton - working with Dazn - had it particularly wide for the challenger, giving Buatsi just only one stanza.
Buatsi moves on, but with the caliber of power puncher Benavidez, and Russian champion Dmitry Bivol ruling the division, the journey to titles - based on this performance - still looks steep.
Ricky Hatton Tribute Inspires Local Rivalry Fight
In the secondary fight, Lyndon Arthur beat Bradley Rea by split-decision in a excellent all-Manchester fight to secure the continental title.
The arena fell silent for a deeply poignant tribute ahead of the contest as a bell ceremony sounded in honor of Manchester's own Ricky Hatton, who died 46 years old in recently.
It was the premier televised fight night in the urban center since the passing of Hatton. As the concluding sound disappeared, the quiet transitioned to a shout of "only one Hatton".
The action inside the ropes reflected the feeling. Arthur was floored by a left hook flush on the face in the early round, rising shakily to his feet on the referee's count.
But the traditional red equipment of the fighter soon came forward again. Across the ring, the opponent - in opposing blue - was injured soon, significant bruising forming under his orbital area as the duo exchanged punishing blows.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, matched the intensity with powerful upward punches as the intensity seldom decreased over twelve rounds.
Arthur barely secured the result with scoring tallies of even score, narrow lead and clearer margin, but both fighters were relentless and full of heart, everything their inspiration Hatton represented.
