UK light-heavyweight Buatsi made a winning yet disappointing debut to his career under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a judges' verdict in a close 10-round contest at the Manchester venue.
But the challenger found success, landing some telling individual punches in a fight where the approaches never quite clicked, with excessive holding disrupting the fight.
The officials had it 96-94 for to the winner, with the remaining official a even score.
"It wasn't my finest showing but what do champions do? They win," Buatsi stated in the ringside as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an thrilling contest with his previous opponent in last winter - to secure a 20th career victory.
Several boxing experts thought the challenger, thirty-one, merited the victory but the Derbyshire fighter endured the second setback of his 28-fight career.
Buatsi Earns Win in Dull Match
Buatsi's progress has plateaued in recent years through management issues and long spells of inactivity.
Once tipped as the next star of British boxing, he now stands trying to achieve expectations - possibly in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors ready to be aggressive in a tentative initial rounds.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was making just his second fight at the higher weight class.
By the middle rounds, the underdog had made it competitive, causing problems for the favorite, who utilized a protective stance to edge the better stanzas.
The crowd's patience wore thin because of regular grabbing, with Parker slipping to the canvas several times during clinches.
Parker closed well, but several stanzas were challenging to assess. However, previous titleholder Carl Frampton - providing analysis for the broadcast network - had it particularly wide for Parker, giving Buatsi just a single round.
The victor progresses, but with the caliber of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - on this evidence - still seems difficult.
Ricky Hatton Memorial Fuels Local Rivalry Contest
In the co-main event, Lyndon Arthur overcame Rea by split-decision in a terrific all-Manchester contest to capture the European light heavyweight belt.
The arena became quiet for a deeply poignant tribute prior to the bout as 10 bells rang in remembrance of local hero Hatton, who succumbed 46 years old in recently.
It was the first major televised fight night in the city since Hatton's death. As the concluding sound faded, the silence gave way to a roar of "only one Ricky Hatton".
The competition within the ring matched the emotion. Arthur was knocked down by a left hook squarely on the jaw in the second round, getting up unsteadily to his footing on the eight count.
But the traditional red equipment of Arthur soon advanced again. From the other corner, Rea - in rival City blue - was damaged quickly, heavy swelling forming under his face as the fighters exchanged hard punches.
Rea, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with stinging uppercuts as the action rarely dropped over the full distance.
Arthur edged the decision with official scores of 114-114, narrow lead and clearer margin, but the two athletes were persistent and courageous, exactly what their idol Hatton represented.
