British light-heavyweight Buatsi earned a win yet underwhelming beginning to life under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a tight 10-round contest at the Co-op Live Arena.
But Parker landed significant shots, connecting with powerful individual punches in a contest where the styles never quite clicked, with constant grabbing disrupting the fight.
The officials scored it 96-94 in favor to Buatsi, with the remaining official a 95-95.
"It wasn't my best display but what do champions do? They succeed," Buatsi stated in the arena as he was faced negative reactions from the crowd.
The Londoner returned to winning ways after his initial pro loss - an thrilling contest with his previous opponent in February - to earn a 20th career victory.
Several boxing experts felt the challenger, 31, deserved the victory but the Derbyshire fighter endured the second loss of his 28-fight career.
Buatsi Secures Win in Uneventful Match
His career development has plateaued in recent times through promotional disputes and long spells of inactivity.
Previously predicted as the next star of the British fight scene, he now is positioned trying to fulfil that early promise - possibly in what feels like a final roll of the dice - under fresh management.
He started carefully, with the two boxers willing to be aggressive in a cagey initial rounds.
The challenger, whose sole prior loss came at super-middleweight against John Ryder in two years ago after suffering a hand injury during the bout, was competing in only 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 solid defense to barely take the more effective periods.
The spectators' acceptance decreased amid frequent holding, with Parker going down various instances during clinches.
Parker ended stronger, but many rounds were hard to judge. However, former world champion Carl Frampton - commentating on Dazn - had it strongly leaning for Parker, giving Buatsi just only one stanza.
Buatsi moves on, but with the likes of power puncher David Benavidez, and Russian champion Bivol leading the category, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Tribute Motivates Local Rivalry Battle
In the supporting bout, Lyndon Arthur overcame Bradley Rea by split-decision in a terrific all-Manchester battle to capture the European light-heavyweight championship.
The venue fell silent for a profoundly moving memorial ahead of the contest as a bell ceremony tolled in honor of the city's native Ricky Hatton, who died at age 46 in last month.
It was the premier televised boxing event in the location since Hatton's passing. As the concluding sound faded, the quiet transitioned to a chant of "only one Hatton".
The fighting during the bout matched the emotion. Arthur was sent to the canvas by a powerful punch squarely on the face in the early round, rising shakily to his feet on the eight count.
But the Manchester United-red attire of Arthur soon pressed ahead again. Across the ring, Rea - in competitive blue - was damaged quickly, heavy swelling appearing under his orbital area as the pair landed powerful shots.
Rea, 27, landed power punches but Arthur, thirty-four, fought fire with fire with effective uppercuts as the intensity rarely dropped over 12 rounds.
Arthur barely secured the decision with scoring tallies of even score, 115-113 and wider gap, but the two athletes were persistent and courageous, everything their hero Hatton stood for.
