UK light-heavyweight Buatsi made a winning yet underwhelming debut to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a judges' verdict in a tight ten-round bout at the boxing arena.
But Parker found success, landing some telling individual punches in a fight where the styles didn't complement each other, with constant grabbing disrupting the action.
The scoring judges judged it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my best showing but what defines champions? They succeed," the victor commented in the ringside as he was faced disapproval from the spectators.
The British fighter returned to winning ways after his first professional defeat - an epic battle with Callum Smith in February - to earn a twentieth professional win.
Various analysts thought the challenger, thirty-one, merited the decision but the British boxer experienced the second setback of his 28-fight professional journey.
The Champion Secures Triumph in Slow Affair
His career development has stalled in recent years through promotional disputes and long spells of inactivity.
Once tipped as the rising talent of UK boxing, he now finds himself trying to achieve expectations - possibly in what seems like a final roll of the dice - under fresh management.
He opened tentatively, with the two boxers prepared to be aggressive in a calculated opening few rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand in the contest, was making just his second appearance at light heavyweight.
By the middle rounds, Parker had made it competitive, creating difficulties for the favorite, who utilized a protective stance to narrowly win the better periods.
The crowd's patience decreased because of regular grabbing, with Parker falling to the floor multiple occasions during grappling.
The underdog finished the stronger, but several stanzas were difficult to score. Although, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for the challenger, giving Buatsi just one round.
Buatsi moves on, but with the presence of hard hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - judging by this showing - still looks steep.
Ricky Hatton Memorial Inspires Manchester Derby Battle
In the supporting bout, Arthur overcame Rea by close verdict in a terrific all-Manchester fight to win the European light heavyweight belt.
The stadium became quiet for a extremely emotional memorial prior to the bout as a bell ceremony sounded in remembrance of local hero Hatton, who died aged 46 in recently.
It was the initial significant broadcast fight night in the city since Hatton's passing. As the concluding sound ended, the silence became a chant of "there's just one Hatton".
The action during the bout equaled the sentiment. The eventual winner was knocked down by a left hook flush on the chin in the second round, rising shakily to his position on the eight count.
But the red-colored attire of Arthur soon advanced again. Across the ring, Rea - in rival City blue - was damaged soon, noticeable damage appearing under his orbital area as the pair landed hard punches.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur narrowly won the verdict with official scores of draw, 115-113 and 115-112, but both fighters were determined and full of heart, everything their inspiration the legend represented.
