UK light heavyweight Buatsi made a winning yet disappointing debut to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a split decision in a competitive ten-round contest at the Co-op Live Arena.
But Parker had his moments, landing some telling clean blows in a contest where the approaches failed to mesh, with frequent clinching spoiling the action.
The officials judged it 96-94 for to the winner, with the third a 95-95 draw.
"It wasn't my greatest showing but what do champions do? They prevail," Buatsi commented in the arena as he was faced disapproval from the audience.
The British fighter bounced back after his maiden career setback - an memorable fight with Callum Smith in February - to earn a 20th career victory.
Some ringside observers thought Parker, 31, should have been awarded the win but the contender endured the second setback of his 28-match professional journey.
Buatsi Earns Win in Uneventful Match
His career development has plateaued in recent years through management issues and considerable time of inactivity.
Once tipped as the future of British boxing, he now stands trying to achieve expectations - possibly in what seems like a final roll of the dice - under fresh management.
He began cautiously, with the two boxers prepared to overcommit in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in 2022 after breaking his hand in the contest, was competing in only his second fight at the higher weight class.
By the halfway stage, the underdog had kept it close, creating difficulties for Buatsi, who operated with a solid defense to barely take the more effective periods.
The spectators' acceptance wore thin because of regular grabbing, with the challenger going down various instances during grappling.
The underdog finished the stronger, but several stanzas were challenging to assess. However, ex-champion Carl Frampton - working with Dazn - had it particularly wide for Parker, scoring for Buatsi just a single round.
The victor moves on, but with the likes of power puncher David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Hatton Homage Inspires Manchester Derby Fight
In the supporting bout, Lyndon Arthur overcame Bradley Rea by split-decision in a outstanding local rivalry fight to secure the European light heavyweight belt.
The arena became quiet for a extremely emotional memorial before the fight as a bell ceremony rang in memory of Manchester's own Hatton, who died aged 46 in last month.
It was the premier televised boxing event in the location since Hatton's death. As the final chime disappeared, the quiet transitioned to a roar of "only one Hatton".
The action during the bout equaled the emotion. Arthur was floored by a left hook squarely on the chin in the initial stage, standing uncertainly to his position on the count of eight.
But the traditional red shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in opposing blue - was damaged soon, significant bruising appearing under his face as the duo traded punishing blows.
The challenger, 27, landed power punches but Arthur, thirty-four, responded in kind with stinging uppercuts as the intensity rarely dropped over twelve rounds.
The victor edged the result with judges scorecards of 114-114, narrow lead and wider gap, but both fighters were relentless and full of heart, exactly what their inspiration Hatton stood for.
