UK light-heavyweight Buatsi earned a win yet underwhelming debut to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a majority decision in a close ten-round fight at the Manchester venue.
But Parker landed significant shots, connecting with powerful single shots in a fight where the approaches didn't complement each other, with constant grabbing spoiling the fight.
Two judges judged it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my greatest performance but what defines champions? They win," the victor said in the ring as he was faced negative reactions from the spectators.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in last winter - to claim a 20th career victory.
Several boxing experts thought the challenger, thirty-one, merited the victory but the British boxer endured the second defeat of his 28-bout career.
The Champion Earns Win in Uneventful Match
His career development has plateaued in recent times through contract problems and long spells of inactivity.
Once tipped as the next star of British boxing, he now stands trying to realize his potential - maybe in what seems like a last chance - under new promotional backing.
He opened tentatively, with both competitors ready to be aggressive in a cagey opening few rounds.
Parker, whose single earlier setback came at super-middleweight against John Ryder in two years ago after breaking his hand during the bout, was participating in his second bout at light heavyweight.
By the middle rounds, the underdog had kept it close, making life awkward for Buatsi, who worked behind a solid defense to narrowly win the better periods.
The spectators' acceptance wore thin during regular grabbing, with the challenger slipping to the canvas several times during grappling.
The underdog finished the stronger, but several stanzas were challenging to assess. However, former world champion the boxing analyst - working with the broadcast network - had it strongly leaning for the challenger, giving Buatsi just one round.
Buatsi advances, but with the presence of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Tribute Fuels All-Manchester Contest
In the co-main event, Lyndon Arthur defeated Bradley Rea by close verdict in a excellent local rivalry fight to win the European light-heavyweight championship.
The arena fell silent for a extremely emotional homage before the fight as 10 bells tolled in remembrance of Manchester's own Hatton, who passed away 46 years old in last month.
It was the premier televised match card in the location since Hatton's death. As the final chime faded, the silence gave way to a shout of "there's only one Ricky Hatton".
The competition within the ring reflected the sentiment. Arthur was floored by a significant blow squarely on the jaw in the early round, getting up unsteadily to his feet on the count of eight.
But the Manchester United-red shorts of Arthur soon came forward again. From the other corner, the opponent - in rival City blue - was damaged quickly, significant bruising forming under his eye as the pair exchanged punishing blows.
Rea, twenty-seven, delivered effective strikes but Arthur, 34, responded in kind with powerful upward punches as the pace hardly diminished over 12 rounds.
The victor edged the result with scoring tallies of even score, close margin and 115-112, but the two athletes were persistent and brave, everything their inspiration Hatton represented.
