British light-heavyweight Buatsi earned a win yet underwhelming start to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a majority decision in a close 10-round fight at the Co-op Live Arena.
But the challenger found success, connecting with powerful individual punches in a fight where the approaches didn't complement each other, with constant grabbing marring the contest.
The officials had it 96-94 in favor to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what do champions do? They prevail," Buatsi commented in the ringside as he was greeted with negative reactions from the crowd.
The Londoner returned to winning ways after his first professional defeat - an thrilling contest with Callum Smith in February - to secure a 20th career victory.
Several boxing experts thought Parker, thirty-one, should have been awarded the victory but the contender experienced the second defeat of his 28-match career.
The Champion Claims Triumph in Dull Encounter
The fighter's advancement has slowed in recent years through promotional disputes and considerable time of lack of fights.
Previously predicted as the next star of British boxing, he now is positioned trying to fulfil that early promise - possibly in what seems like a last chance - under fresh management.
He started carefully, with both competitors prepared to overcommit in a calculated initial rounds.
The challenger, whose sole prior loss came at super-middleweight against John Ryder in 2022 after damaging his hand during the bout, was making just his second fight at the higher weight class.
By the halfway stage, the underdog had kept it close, creating difficulties for the favorite, who operated with a protective stance to barely take the cleaner periods.
The spectators' acceptance diminished during constant clinching, with Parker going down multiple occasions during grappling.
Parker ended stronger, but many rounds were hard to judge. Nevertheless, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it particularly wide for the challenger, awarding Buatsi just one round.
The victor advances, but with the likes of heavy hitter David Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still appears challenging.
Hatton Memorial Fuels All-Manchester Fight
In the co-main event, Arthur beat Bradley Rea by close verdict in a excellent Manchester vs Manchester contest to capture the European light heavyweight belt.
The stadium grew hushed for a deeply poignant tribute before the fight as ten bells rang in memory of Manchester's own Ricky Hatton, who passed away at age 46 in September.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the final chime ended, the stillness became a roar of "there's just one Hatton".
The action within the ring reflected the feeling. Arthur was sent to the canvas by a left hook squarely on the chin in the initial stage, standing uncertainly to his footing on the eight count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, Rea - in rival City blue - was injured early, heavy swelling developing under his face as the duo landed hard punches.
Rea, 27, landed power punches but the champion, 34, matched the intensity with stinging uppercuts as the intensity hardly diminished over 12 rounds.
Arthur edged the verdict with judges scorecards of even score, narrow lead and 115-112, but each competitor were relentless and brave, everything their hero the legend represented.
