UK light heavyweight Buatsi earned a win yet underwhelming beginning to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's activity level appeared to earn him a judges' verdict in a tight 10-round bout at the Manchester venue.
But the challenger had his moments, delivering effective single shots in a fight where the techniques failed to mesh, with excessive holding spoiling the fight.
Two judges judged it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest showing but how do champions respond? They win," the victor commented in the arena as he was met by boos from the audience.
The Londoner got back to winning after his maiden career setback - an epic battle with his previous opponent in February - to claim a twentieth professional win.
Various analysts believed the challenger, thirty-one, deserved the decision but the Derbyshire fighter suffered the second setback of his 28-match career.
Buatsi's progress has plateaued in recent times through contract problems and long spells of lack of fights.
Once tipped as the future of UK boxing, he now finds himself trying to realize his potential - perhaps in what feels like a final roll of the dice - under fresh management.
He started carefully, with neither fighter ready to take risks in a calculated opening few rounds.
The challenger, whose sole prior loss 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 halfway stage, the underdog had kept it close, creating difficulties for the favorite, who operated with a solid defense to barely take the more effective stanzas.
The audience's tolerance wore thin during constant clinching, with Parker falling to the floor several times during close exchanges.
The underdog closed well, but several stanzas were challenging to assess. However, ex-champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
Buatsi progresses, but with the caliber of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - on this evidence - still appears challenging.
In the co-main event, Lyndon Arthur beat Bradley Rea by split-decision in a terrific Manchester vs Manchester contest to secure the European light heavyweight belt.
The stadium fell silent for a profoundly moving tribute ahead of the contest as a bell ceremony tolled in memory of the city's native Ricky Hatton, who died 46 years old in recently.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the final chime disappeared, the stillness became a shout of "there's only one Ricky Hatton".
The competition within the ring equaled the emotion. The eventual winner was sent to the canvas by a significant blow squarely on the face in the second round, rising shakily to his footing on the eight count.
But the traditional red attire of Arthur soon advanced again. From the other corner, the opponent - in competitive blue - was injured early, noticeable damage forming under his orbital area as the duo exchanged punishing blows.
Rea, 27, landed power punches but the champion, thirty-four, fought fire with fire with powerful upward punches as the action rarely dropped over 12 rounds.
Arthur barely secured the verdict with judges scorecards of draw, 115-113 and wider gap, but both fighters were determined and courageous, exactly what their hero the legend embodied.