UK light-heavyweight Buatsi made a winning yet disappointing beginning to his career under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output appeared to earn him a majority decision in a close ten-round contest at the Co-op Live Arena.
But Parker landed significant shots, delivering effective single shots in a contest where the approaches didn't complement each other, with excessive holding disrupting the action.
Two judges had it 96-94 for to Buatsi, with the third a 95-95.
"It wasn't my finest display but what do champions do? They prevail," the victor stated in the ring as he was greeted with negative reactions from the spectators.
The Londoner bounced back after his initial pro loss - an memorable fight with his previous opponent in February - to earn a twentieth professional win.
Several boxing experts felt Parker, 31, should have been awarded the victory but the Derbyshire fighter suffered the second loss of his 28-fight career.
The Champion Secures Win in Uneventful Match
His career development has plateaued in recent times through contract problems and considerable time of lack of fights.
Previously predicted as the future of British boxing, he now is positioned trying to fulfil that early promise - maybe in what feels like a ultimate opportunity - under recent support.
He started carefully, with both competitors ready to take risks in a tentative opening few rounds.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after damaging his hand in the contest, was competing in only his second fight at the higher weight class.
By the halfway stage, the underdog had kept it close, making life awkward for the favorite, who utilized a tight guard to edge the cleaner stanzas.
The audience's tolerance wore thin because of frequent holding, with the challenger slipping to the canvas several times during close exchanges.
Parker ended stronger, but multiple periods were challenging to assess. Nevertheless, ex-champion Carl Frampton - commentating on Dazn - had it particularly wide for Parker, awarding Buatsi just only one stanza.
The victor advances, but with the likes of heavy hitter David Benavidez, and Russian champion Bivol dominating the weight class, the path to championship success - judging by this showing - still seems difficult.
Ricky Hatton Tribute Fuels Local Rivalry Battle
In the co-main event, Arthur beat Bradley Rea by divided decision in a terrific local rivalry fight to capture the European light heavyweight belt.
The venue fell silent for a extremely emotional tribute before the fight as ten bells sounded in honor of local hero Hatton, who passed away 46 years old in recently.
It was the first major televised fight night in the location since the passing of Hatton. As the concluding sound ended, the quiet transitioned to a chant of "only one Ricky Hatton".
The fighting during the bout equaled the emotion. The eventual winner was knocked down by a left hook squarely on the chin in the early round, rising shakily to his footing on the eight count.
But the traditional red equipment of Arthur soon came forward again. Across the ring, Rea - in opposing blue - was marked up soon, noticeable damage appearing under his face as the fighters exchanged powerful shots.
The challenger, twenty-seven, landed power punches but Arthur, 34, matched the intensity with effective uppercuts as the pace seldom decreased over twelve rounds.
Arthur narrowly won the result with scoring tallies of even score, 115-113 and clearer margin, but each competitor were determined and full of heart, all the qualities their idol Hatton represented.
