British light heavyweight Buatsi made a winning yet underwhelming start to his career under new promoters with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a judges' verdict in a close 10-round bout at the Co-op Live Arena.
But Parker found success, connecting with powerful individual punches in a match where the approaches failed to mesh, with frequent clinching spoiling the fight.
The scoring judges scored it 96-94 in favor to Buatsi, with the third a even score.
"It wasn't my greatest display but what do champions do? They win," the victor said in the ringside as he was faced negative reactions from the audience.
The British fighter bounced back after his first professional defeat - an thrilling contest with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers believed Parker, thirty-one, should have been awarded the decision but the Derbyshire fighter endured the second loss of his 28-fight professional journey.
Buatsi Claims Victory in Slow Match
His career development has plateaued in recent times through contract problems and considerable time of inactivity.
Once tipped as the rising talent of British boxing, he now finds himself trying to achieve expectations - perhaps in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with both competitors prepared to take risks in a tentative opening few rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in two years ago after suffering a hand injury during the bout, was making just his second appearance at light-heavyweight.
By the fight's midpoint, Parker had kept it close, creating difficulties for the favorite, who utilized a protective stance to edge the more effective stanzas.
The audience's tolerance decreased during regular grabbing, with Parker slipping to the canvas multiple occasions during clinches.
The underdog closed well, but several stanzas were hard to judge. Although, former world champion Carl Frampton - commentating on the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just one round.
The victor advances, but with the caliber of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Hatton Homage Inspires All-Manchester Contest
In the co-main event, Arthur overcame Bradley Rea by divided decision in a excellent local rivalry fight to capture the continental belt.
The venue grew hushed for a extremely emotional homage prior to the bout as a bell ceremony rang in memory of local hero Ricky Hatton, who passed away at age 46 in recently.
It was the first major televised fight night in the location since Hatton's death. As the final chime disappeared, the quiet gave way to a chant of "there's just one Hatton".
The action during the bout equaled the sentiment. Arthur was floored by a left hook directly to the face in the initial stage, rising shakily to his feet on the referee's count.
But the red-colored shorts of Arthur soon advanced again. On the opposite side, the opponent - in competitive blue - was marked up early, heavy swelling developing under his orbital area as the fighters traded powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, fought fire with fire with powerful upward punches as the pace rarely dropped over 12 rounds.
The victor edged the decision with judges scorecards of 114-114, narrow lead and clearer margin, but the two athletes were determined and brave, all the qualities their hero Hatton represented.
