British light heavyweight Buatsi earned a win yet unimpressive debut to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a close ten-round contest at the Manchester venue.
But Parker found success, landing some telling single shots in a fight where the approaches never quite clicked, with excessive holding disrupting the contest.
Two judges judged it 96-94 in favor to the winner, with the third a even score.
"It wasn't my finest display but how do champions respond? They prevail," Buatsi said in the ringside as he was met by disapproval from the audience.
The Londoner bounced back after his initial pro loss - an thrilling contest with his previous opponent in February - to earn a twentieth professional win.
Some ringside observers believed the challenger, thirty-one, merited the win but the contender endured the second setback of his 28-match career.
Buatsi Secures Victory in Slow Affair
His career development has plateaued in recent times through contract problems and long spells of inactivity.
Earlier forecast as the next star of UK boxing, he now is positioned trying to fulfil that early promise - perhaps in what appears to be a final roll of the dice - under recent support.
He began cautiously, with both competitors prepared to take risks in a cagey opening few rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in two years ago after damaging his hand in the contest, was making just his second bout at light heavyweight.
By the halfway stage, Parker had made it competitive, making life awkward for Buatsi, who operated with a tight guard to edge the cleaner stanzas.
The crowd's patience decreased during frequent holding, with Parker slipping to the canvas multiple occasions during clinches.
The underdog closed well, but several stanzas were hard to judge. Nevertheless, former world champion the boxing analyst - commentating on Dazn - had it strongly leaning for Parker, awarding Buatsi just only one stanza.
Buatsi progresses, but with the presence of hard hitter Benavidez, and Russian champion Bivol ruling the division, the path to championship success - on this evidence - still appears challenging.
Ricky Hatton Memorial Fuels Manchester Derby Contest
In the co-main event, Lyndon Arthur overcame Bradley Rea by close verdict in a terrific all-Manchester battle to secure the European light-heavyweight belt.
The arena fell silent for a deeply poignant homage before the fight as a bell ceremony sounded in honor of local hero Hatton, who died 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 faded, the quiet became a roar of "there's only one Ricky Hatton".
The fighting within the ring reflected the emotion. Arthur was floored by a powerful punch directly to the jaw in the second round, standing uncertainly to his feet on the count of eight.
But the red-colored shorts of Arthur soon advanced again. Across the ring, Rea - in competitive blue - was marked up quickly, significant bruising appearing under his face as the pair traded hard punches.
The challenger, 27, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the pace seldom decreased over twelve rounds.
The victor edged the decision with official scores of draw, 115-113 and 115-112, but each competitor were determined and courageous, exactly what their idol the legend embodied.
