British light heavyweight Buatsi made a winning yet disappointing beginning to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate likely gained him a majority decision in a competitive ten-round fight at the Co-op Live Arena.
But the challenger found success, delivering effective individual punches in a match where the styles didn't complement each other, with frequent clinching disrupting the fight.
The scoring judges scored it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my best showing but what defines champions? They prevail," the victor said in the ring as he was greeted with boos from the audience.
The Londoner got back to winning after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a 20th career victory.
Various analysts felt the challenger, 31, deserved the win but the Derbyshire fighter experienced the second defeat of his 28-match career.
The Champion Claims Triumph in Slow Match
Buatsi's progress has slowed in the past few years through promotional disputes and extended periods of lack of fights.
Once tipped as the next star of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter willing to overcommit in a tentative initial rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in 2022 after suffering a hand injury mid-fight, was participating in his second bout at light-heavyweight.
By the fight's midpoint, the underdog had stayed in contention, causing problems for Buatsi, who utilized a solid defense to barely take the more effective rounds.
The spectators' acceptance wore thin because of constant clinching, with Parker going down various instances during clinches.
The underdog closed well, but many rounds were challenging to assess. Although, former world champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for the challenger, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the presence of power puncher Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - based on this performance - still appears challenging.
Hatton Tribute Fuels Manchester Derby Fight
In the secondary fight, Arthur overcame Rea by divided decision in a terrific all-Manchester fight to capture the European light-heavyweight title.
The venue became quiet for a profoundly moving homage ahead of the contest as 10 bells tolled in remembrance of local hero Hatton, who died aged 46 in September.
It was the premier televised match card in the city since Hatton's passing. As the concluding sound ended, the stillness gave way to a shout of "only one Hatton".
The competition inside the ropes matched the emotion. Arthur was sent to the canvas by a left hook directly to the chin in the initial stage, rising shakily to his footing on the eight count.
But the Manchester United-red shorts of Arthur soon came forward again. On the opposite side, Rea - in opposing blue - was damaged quickly, significant bruising appearing under his orbital area as the duo traded punishing blows.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with powerful upward punches as the action hardly diminished over 12 rounds.
Arthur edged the decision with scoring tallies of 114-114, close margin and wider gap, but the two athletes were relentless and full of heart, exactly what their hero the legend embodied.
