British light-heavyweight Buatsi secured a victory yet unimpressive debut to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a judges' verdict in a close ten-round fight at the boxing arena.
But the challenger landed significant shots, connecting with powerful clean blows in a fight where the approaches never quite clicked, with constant grabbing marring the fight.
The officials judged it 96-94 to the winner, with the third a 95-95 draw.
"It wasn't my finest showing but what do champions do? They prevail," Buatsi said in the ringside as he was greeted with negative reactions from the crowd.
The Londoner returned to winning ways after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a 20th career victory.
Some ringside observers believed the challenger, 31, should have been awarded the victory but the Derbyshire fighter suffered the second defeat of his 28-fight career.
Buatsi Secures Victory in Uneventful Match
Buatsi's progress has slowed in recent times through management issues and considerable time of lack of fights.
Earlier forecast as the next star of UK boxing, he now stands trying to fulfil that early promise - perhaps in what seems like a final roll of the dice - under fresh management.
He started carefully, with the two boxers prepared to take risks in a tentative opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was competing in only his second fight at the higher weight class.
By the halfway stage, the underdog had stayed in contention, causing problems for the favorite, who utilized a solid defense to narrowly win the more effective stanzas.
The audience's tolerance wore thin during constant clinching, with Parker falling to the floor various instances during grappling.
Parker closed well, but several stanzas were difficult to score. Although, former world champion Carl Frampton - commentating on Dazn - had it strongly leaning for the challenger, giving Buatsi just only one stanza.
The victor moves on, but with the caliber of power puncher Benavidez, and Russian champion Bivol ruling the division, the road to world glory - judging by this showing - still looks steep.
Ricky Hatton Memorial Fuels Local Rivalry Battle
In the secondary fight, Lyndon Arthur overcame Bradley Rea by divided decision in a excellent local rivalry battle to secure the European light-heavyweight title.
The stadium became quiet for a profoundly moving tribute before the fight as ten bells rang in honor of Manchester's own Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the final chime ended, the quiet became a shout of "there's just one Ricky Hatton".
The competition inside the ropes reflected the emotion. The eventual winner was sent to the canvas by a left hook flush on the jaw in the early round, standing uncertainly to his position on the count of eight.
But the Manchester United-red shorts of Arthur soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was marked up soon, noticeable damage developing under his orbital area as the duo landed punishing blows.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, responded in kind with powerful upward punches as the intensity hardly diminished over 12 rounds.
Arthur narrowly won the result with official scores of even score, narrow lead and clearer margin, but the two athletes were persistent and full of heart, all the qualities their hero Hatton stood for.
