British light heavyweight Buatsi secured a victory yet disappointing beginning to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a majority decision in a tight 10-round bout at the Manchester venue.
But the challenger landed significant shots, connecting with powerful individual punches in a contest where the approaches never quite clicked, with constant grabbing marring the action.
Two judges scored it 96-94 for to the winner, with the remaining official a 95-95.
"It wasn't my finest performance but what do champions do? They win," the victor stated in the ringside as he was greeted with boos from the audience.
The Londoner bounced back after his initial pro loss - an memorable fight with his previous opponent in February - to claim a 20th career victory.
Various analysts believed the challenger, thirty-one, should have been awarded the win but the Derbyshire fighter experienced the second loss of his 28-bout career.
Buatsi Secures Victory in Uneventful Affair
Buatsi's progress has plateaued in recent times through promotional disputes and extended periods of inactivity.
Previously predicted as the next star of the British fight scene, he now stands trying to fulfil that early promise - maybe in what feels like a final roll of the dice - under recent support.
He began cautiously, with neither fighter willing to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after breaking his hand in the contest, was making just his second fight at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who operated with a solid defense to narrowly win the better stanzas.
The spectators' acceptance wore thin because of regular grabbing, with Parker slipping to the canvas multiple occasions during clinches.
Parker finished the stronger, but many rounds were challenging to assess. However, ex-champion the boxing analyst - working with Dazn - had it significantly in favor for Parker, giving Buatsi just a single round.
Buatsi moves on, but with the presence of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the road to world glory - on this evidence - still seems difficult.
Hatton Memorial Inspires Local Rivalry Fight
In the supporting bout, Lyndon Arthur beat Rea by close verdict in a excellent local rivalry contest to capture the continental title.
The arena became quiet for a deeply poignant memorial ahead of the contest as a bell ceremony tolled in memory of Manchester's own Ricky Hatton, who passed away at age 46 in September.
It was the premier televised fight night in the location since the passing of Hatton. As the concluding sound ended, the quiet transitioned to a shout of "there's only one Hatton".
The fighting inside the ropes reflected the feeling. The eventual winner was knocked down by a significant blow squarely on the chin in the second round, getting up unsteadily to his footing on the count of eight.
But the red-colored shorts of Arthur soon came forward again. From the other corner, the opponent - in rival City blue - was damaged soon, heavy swelling appearing under his orbital area as the fighters landed hard punches.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, fought fire with fire with effective uppercuts as the action hardly diminished over twelve rounds.
Arthur edged the verdict with scoring tallies of even score, close margin and 115-112, but each competitor were determined and courageous, all the qualities their inspiration the legend represented.
