British light heavyweight Buatsi made a winning yet disappointing beginning to life under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a competitive ten-round contest at the Co-op Live Arena.
But Parker had his moments, delivering effective single shots in a match where the styles didn't complement each other, with frequent clinching marring the action.
The officials judged it 96-94 for to the winner, with the final judge a 95-95.
"It wasn't my finest performance but what defines champions? They prevail," Buatsi said in the ring as he was met by disapproval from the spectators.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Some ringside observers thought the challenger, thirty-one, merited the win but the British boxer endured the second defeat of his 28-bout career.
Buatsi Claims Win in Dull Affair
The fighter's advancement has slowed in the past few years through management issues and long spells of inactivity.
Earlier forecast as the next star of British boxing, he now finds himself trying to fulfil that early promise - perhaps in what feels like a final roll of the dice - under fresh management.
He opened tentatively, with neither fighter ready to be aggressive in a tentative initial rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in two years ago after damaging his hand in the contest, was making just his second appearance at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, creating difficulties for the favorite, who utilized a solid defense to edge the cleaner stanzas.
The spectators' acceptance diminished during regular grabbing, with the challenger going down various instances during clinches.
The underdog ended stronger, but several stanzas were challenging to assess. However, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for Parker, scoring for Buatsi just one round.
Buatsi progresses, but with the caliber of hard hitter Benavidez, and Russian star Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Hatton Homage Inspires All-Manchester Contest
In the secondary fight, Arthur defeated Bradley Rea by divided decision in a outstanding Manchester vs Manchester contest to capture the European light-heavyweight championship.
The arena grew hushed for a extremely emotional homage prior to the bout as ten bells tolled in memory of local hero Ricky Hatton, who passed away aged 46 in recently.
It was the initial significant broadcast boxing event in the location since Hatton's death. As the concluding sound faded, the stillness gave way to a chant of "there's only one Hatton".
The competition inside the ropes equaled the emotion. Arthur was floored by a significant blow flush on the jaw in the second round, getting up unsteadily to his position on the referee's count.
But the red-colored equipment of Arthur soon came forward again. Across the ring, Rea - in opposing blue - was injured early, significant bruising forming under his eye as the duo traded punishing blows.
The challenger, 27, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the action rarely dropped over 12 rounds.
The victor barely secured the verdict with scoring tallies of 114-114, narrow lead and 115-112, but the two athletes were determined and full of heart, exactly what their hero the legend stood for.
