UK light heavyweight Buatsi made a winning yet unimpressive beginning to life under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a majority decision in a competitive ten-round contest at the Co-op Live Arena.
But Parker had his moments, landing some telling single shots in a fight where the approaches didn't complement each other, with excessive holding disrupting the contest.
The scoring judges had it 96-94 for to the winner, with the third a even score.
"It wasn't my finest showing but what do champions do? They win," the victor said in the arena as he was greeted with disapproval from the audience.
The British fighter got back to winning after his first professional defeat - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Several boxing experts believed Parker, 31, should have been awarded the decision but the Derbyshire fighter experienced the second loss of his 28-bout career.
Buatsi Secures Victory in Dull Match
The fighter's advancement has plateaued in recent years through contract problems and long spells of inactivity.
Once tipped as the next star of UK boxing, he now stands trying to achieve expectations - perhaps in what feels like a last chance - under recent support.
He began cautiously, with neither fighter ready to overcommit in a cagey opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in 2022 after breaking his hand in the contest, was making just his second bout at light heavyweight.
By the halfway stage, Parker had made it competitive, causing problems for Buatsi, who worked behind a tight guard to narrowly win the better stanzas.
The audience's tolerance wore thin during frequent holding, with Parker slipping to the canvas several times during clinches.
Parker ended stronger, but multiple periods were difficult to score. However, former world champion Carl Frampton - commentating on Dazn - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Homage Motivates Local Rivalry Fight
In the secondary fight, Lyndon Arthur overcame Bradley Rea by divided decision in a excellent local rivalry contest to win the European light heavyweight belt.
The venue became quiet for a deeply poignant homage prior to the bout as ten bells sounded in honor of the city's native Hatton, who died 46 years old in September.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the final chime disappeared, the quiet transitioned to a chant of "only one Ricky Hatton".
The fighting during the bout matched the emotion. Arthur was sent to the canvas by a powerful punch flush on the chin in the early round, standing uncertainly to his footing on the count of eight.
But the Manchester United-red equipment of the fighter soon advanced again. On the opposite side, the opponent - in opposing blue - was marked up quickly, noticeable damage forming under his eye as the pair exchanged powerful shots.
Rea, 27, landed power punches but the champion, thirty-four, responded in kind with effective uppercuts as the intensity rarely dropped over twelve rounds.
The victor edged the decision with scoring tallies of draw, close margin and 115-112, but both fighters were relentless and full of heart, exactly what their hero Hatton represented.
