British light-heavyweight Buatsi secured a victory yet underwhelming start to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a majority decision in a competitive 10-round bout at the Co-op Live Arena.
But Parker landed significant shots, landing some telling clean blows in a fight where the styles never quite clicked, with excessive holding disrupting the fight.
The officials scored it 96-94 in favor to Buatsi, with the third a 95-95 draw.
"It wasn't my best showing but what defines champions? They win," the victor commented in the ring as he was met by boos from the spectators.
The Londoner bounced back after his maiden career setback - an memorable fight with his previous opponent in February - to earn a twentieth professional win.
Various analysts felt the challenger, 31, should have been awarded the win but the contender experienced the second setback of his 28-bout career.
The Champion Earns Victory in Slow Match
The fighter's advancement has plateaued in recent years through management issues and extended periods of inactivity.
Once tipped as the future of British boxing, he now finds himself trying to realize his potential - maybe in what seems like a ultimate opportunity - under new promotional backing.
He opened tentatively, with both competitors prepared to take risks in a cagey 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 in the contest, was participating in his second fight at light-heavyweight.
By the halfway stage, the underdog had made it competitive, creating difficulties for the favorite, who utilized a tight guard to narrowly win the better rounds.
The spectators' acceptance decreased because of constant clinching, with the challenger falling to the floor several times during close exchanges.
The underdog closed well, but several stanzas were hard to judge. However, ex-champion Carl Frampton - providing analysis for Dazn - had it strongly leaning for Parker, awarding Buatsi just one round.
The victor advances, but with the likes of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Memorial Inspires Local Rivalry Fight
In the co-main event, Lyndon Arthur overcame Bradley Rea by divided decision in a outstanding all-Manchester contest to win the European light-heavyweight championship.
The stadium fell silent for a deeply poignant memorial ahead of the contest as 10 bells sounded in remembrance of Manchester's own Hatton, who succumbed aged 46 in September.
It was the premier televised boxing event in the city since the passing of Hatton. As the final chime disappeared, the quiet became a roar of "there's only one Hatton".
The action during the bout equaled the sentiment. The eventual winner was sent to the canvas by a significant blow flush on the face in the early round, getting up unsteadily to his footing on the eight count.
But the Manchester United-red equipment of Arthur soon came forward again. From the other corner, the opponent - in opposing blue - was marked up soon, heavy swelling forming under his orbital area as the duo traded hard punches.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, matched the intensity with stinging uppercuts as the intensity rarely dropped over 12 rounds.
The victor barely secured the decision with scoring tallies of 114-114, 115-113 and 115-112, but each competitor were relentless and brave, exactly what their idol the legend represented.
