British light heavyweight Buatsi secured a victory yet unimpressive start to his career under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's work rate appeared to earn him a split decision in a tight ten-round contest at the Co-op Live Arena.
But the challenger had his moments, delivering effective single shots in a contest where the styles failed to mesh, with excessive holding spoiling the action.
The scoring judges had it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest performance but how do champions respond? They succeed," Buatsi said in the ring as he was faced disapproval from the spectators.
The British fighter bounced back after his maiden career setback - an memorable fight with his previous opponent in February - to secure a twentieth professional win.
Various analysts felt the challenger, thirty-one, should have been awarded the win but the British boxer experienced the second setback of his 28-fight career.
Buatsi Claims Victory in Uneventful Encounter
Buatsi's progress has slowed in the past few years through promotional disputes and considerable time of inactivity.
Once tipped as the future of British boxing, he now is positioned trying to achieve expectations - maybe in what appears to be a final roll of the dice - under recent support.
He opened tentatively, with the two boxers prepared to overcommit in a tentative initial rounds.
The challenger, whose single earlier setback came at super middleweight against John Ryder in 2022 after suffering a hand injury during the bout, was making just his second appearance at light heavyweight.
By the fight's midpoint, Parker had made it competitive, creating difficulties for the favorite, who worked behind a protective stance to barely take the better periods.
The audience's tolerance wore thin because of frequent holding, with Parker slipping to the canvas various instances during close exchanges.
The underdog finished the stronger, but many rounds were difficult to score. Nevertheless, former world champion Carl Frampton - commentating on the broadcast network - had it strongly leaning for Parker, giving Buatsi just one round.
Buatsi moves on, but with the presence of power puncher Benavidez, and Russian champion Bivol leading the category, the path to championship success - on this evidence - still appears challenging.
Ricky Hatton Homage Motivates All-Manchester Fight
In the supporting bout, Lyndon Arthur overcame Bradley Rea by divided decision in a excellent Manchester vs Manchester contest to secure the European light heavyweight championship.
The venue grew hushed for a profoundly moving memorial before the fight as ten bells tolled in memory of local hero Hatton, who passed away aged 46 in September.
It was the initial significant broadcast match card in the urban center since Hatton's death. As the last bell ended, the silence became a shout of "there's only one Hatton".
The fighting inside the ropes equaled the emotion. Arthur was floored by a significant blow directly to the chin in the second round, rising shakily to his position on the eight count.
But the red-colored shorts of Arthur soon came forward again. From the other corner, the opponent - in opposing blue - was injured soon, noticeable damage forming under his orbital area as the fighters landed punishing blows.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with powerful upward punches as the pace hardly diminished over twelve rounds.
The victor barely secured the result with official scores of even score, narrow lead and 115-112, but the two athletes were relentless and full of heart, everything their inspiration Hatton represented.
