British light heavyweight Buatsi earned a win yet underwhelming beginning to life under new promoters 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 competitive 10-round fight at the Co-op Live Arena.
But Parker found success, delivering effective clean blows in a fight where the styles didn't complement each other, with frequent clinching spoiling the fight.
Two judges scored it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest display but what defines champions? They succeed," the victor said in the arena as he was faced negative reactions from the audience.
The British fighter bounced back after his initial pro loss - an thrilling contest with his previous opponent in February - to earn a 20th pro success.
Several boxing experts thought the challenger, thirty-one, merited the victory but the British boxer experienced the second defeat of his 28-match professional journey.
Buatsi Earns Win in Dull Affair
His career development has plateaued in recent years through contract problems and long spells of inactivity.
Previously predicted as the rising talent of UK boxing, he now is positioned trying to fulfil that early promise - perhaps in what seems like a ultimate opportunity - under new promotional backing.
He began cautiously, with both competitors ready to overcommit in a cagey initial rounds.
Parker, whose single earlier setback came at super-middleweight against John Ryder in two years ago after breaking his hand mid-fight, was making just his second fight at light-heavyweight.
By the fight's midpoint, the underdog had stayed in contention, creating difficulties for the favorite, who utilized a tight guard to barely take the better periods.
The spectators' acceptance wore thin because of regular grabbing, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog closed well, but many rounds were hard to judge. However, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just one round.
The victor progresses, but with the presence of heavy hitter David Benavidez, and Russian star Bivol ruling the division, the road to world glory - based on this performance - still appears challenging.
Ricky Hatton Tribute Fuels Local Rivalry Contest
In the secondary fight, Arthur overcame Rea by close verdict in a excellent local rivalry battle to secure the European light-heavyweight belt.
The stadium grew hushed for a extremely emotional homage prior to the bout as 10 bells tolled in honor of Manchester's own Hatton, who died 46 years old in September.
It was the initial significant broadcast fight night in the city since the passing of Hatton. As the concluding sound ended, the silence gave way to a chant of "there's just one Hatton".
The competition during the bout reflected the feeling. Arthur was knocked down by a significant blow squarely on the jaw in the initial stage, rising shakily to his position on the eight count.
But the traditional red attire of Arthur soon pressed ahead again. On the opposite side, the opponent - in rival City blue - was marked up soon, significant bruising appearing under his eye as the pair landed powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, responded in kind with effective uppercuts as the action hardly diminished over 12 rounds.
The victor barely secured the verdict with judges scorecards of 114-114, 115-113 and wider gap, but both fighters were determined and courageous, all the qualities their inspiration the legend stood for.
