UK light-heavyweight Buatsi secured a victory yet disappointing start to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a competitive ten-round fight at the Co-op Live Arena.
But the challenger landed significant shots, delivering effective single shots in a match where the approaches failed to mesh, with excessive holding marring the contest.
The scoring judges judged it 96-94 in favor to the winner, with the third a even score.
"It wasn't my best showing but what do champions do? They prevail," Buatsi said in the ringside as he was faced disapproval from the crowd.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in February - to secure a 20th career victory.
Various analysts felt the challenger, 31, merited the win but the Derbyshire fighter endured the second setback of his 28-fight professional journey.
The Champion Secures Victory in Dull Affair
Buatsi's progress has stalled in recent years through contract problems and long spells of inactivity.
Earlier forecast as the rising talent of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under new promotional backing.
He started carefully, with both competitors prepared to take risks in a tentative initial rounds.
The challenger, whose sole prior loss came at super-middleweight against John Ryder in two years ago after suffering a hand injury in the contest, was making just his second bout at the higher weight class.
By the fight's midpoint, Parker had stayed in contention, making life awkward for the favorite, who operated with a solid defense to barely take the better rounds.
The audience's tolerance diminished during regular grabbing, with Parker slipping to the canvas multiple occasions during clinches.
Parker ended stronger, but several stanzas were difficult to score. Although, ex-champion Carl Frampton - commentating on the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just a single round.
The victor moves on, but with the likes of hard hitter Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still seems difficult.
Hatton Tribute Motivates Manchester Derby Contest
In the supporting bout, Lyndon Arthur overcame Bradley Rea by split-decision in a excellent Manchester vs Manchester battle to capture the European light-heavyweight belt.
The arena fell silent for a profoundly moving memorial prior to the bout as 10 bells tolled in honor of Manchester's own Ricky Hatton, who succumbed at age 46 in September.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the final chime ended, the silence transitioned to a chant of "only one Ricky Hatton".
The fighting within the ring reflected the emotion. Arthur was sent to the canvas by a left hook flush on the jaw in the early round, getting up unsteadily to his footing on the referee's count.
But the Manchester United-red attire of Arthur soon pressed ahead again. From the other corner, the opponent - in opposing blue - was injured quickly, noticeable damage developing under his orbital area as the pair traded powerful shots.
The challenger, twenty-seven, delivered effective strikes but Arthur, 34, fought fire with fire with effective uppercuts as the intensity rarely dropped over twelve rounds.
Arthur narrowly won the result with scoring tallies of 114-114, close margin and clearer margin, but both fighters were persistent and full of heart, everything their hero the legend embodied.
