British light-heavyweight Buatsi secured a victory yet disappointing start to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a split decision in a competitive 10-round bout at the Co-op Live Arena.
But the challenger had his moments, landing some telling single shots in a contest where the techniques never quite clicked, with constant grabbing spoiling the fight.
The officials judged it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my finest showing but what do champions do? They prevail," the victor said in the ring as he was greeted with negative reactions from the audience.
The Londoner got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to earn a 20th pro success.
Various analysts thought the challenger, 31, merited the decision but the contender experienced the second setback of his 28-bout career.
Buatsi Earns Victory in Uneventful Affair
The fighter's advancement has stalled in the past few years through contract problems and extended periods of inactivity.
Earlier forecast as the rising talent of the British fight scene, he now stands trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under new promotional backing.
He opened tentatively, with both competitors prepared to be aggressive in a calculated early stages.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was competing in only his second bout at the higher weight class.
By the halfway stage, the underdog had made it competitive, making life awkward for Buatsi, who utilized a protective stance to edge the better rounds.
The crowd's patience diminished during regular grabbing, with the challenger slipping to the canvas multiple occasions during clinches.
Parker ended stronger, but several stanzas were challenging to assess. Nevertheless, former world champion the boxing analyst - providing analysis for Dazn - had it particularly wide for Parker, awarding Buatsi just one round.
Buatsi moves on, but with the caliber of power puncher David Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - on this evidence - still looks steep.
Hatton Tribute Motivates Manchester Derby Fight
In the secondary fight, Lyndon Arthur defeated Bradley Rea by divided decision in a outstanding local rivalry fight to secure the European light-heavyweight belt.
The stadium became quiet for a deeply poignant homage before the fight as a bell ceremony sounded in remembrance of Manchester's own Hatton, who passed away at age 46 in recently.
It was the premier televised fight night in the location since Hatton's passing. As the last bell ended, the silence became a roar of "there's just one Hatton".
The action inside the ropes equaled the sentiment. The eventual winner was floored by a left hook squarely on the jaw in the initial stage, rising shakily to his feet on the count of eight.
But the Manchester United-red equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in rival City blue - was marked up early, noticeable damage appearing under his orbital area as the fighters exchanged powerful shots.
Rea, twenty-seven, landed power punches but Arthur, 34, matched the intensity with stinging uppercuts as the pace seldom decreased over the full distance.
The victor edged the decision with judges scorecards of even score, narrow lead and wider gap, but the two athletes were persistent and brave, exactly what their inspiration the legend stood for.
