British light heavyweight Buatsi made a winning yet underwhelming start to his career under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic medal winner's punch output appeared to earn him a judges' verdict in a close ten-round bout at the Co-op Live Arena.
But the challenger found success, landing some telling single shots in a contest where the techniques didn't complement each other, with constant grabbing marring the contest.
The scoring judges scored it 96-94 in favor to Buatsi, with the third a even score.
"It wasn't my finest display but what defines champions? They prevail," the victor stated in the ring as he was faced disapproval from the crowd.
The Londoner got back to winning after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a 20th pro success.
Several boxing experts believed Parker, 31, deserved the win but the contender endured the second setback of his 28-fight career.
Buatsi Secures Triumph in Slow Affair
His career development has stalled in recent years through contract problems and long spells of lack of fights.
Once tipped as the next star of British boxing, he now is positioned trying to achieve expectations - possibly in what feels like a final roll of the dice - under new promotional backing.
He opened tentatively, with both competitors ready to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury mid-fight, was competing in only his second fight at the higher weight class.
By the middle rounds, the underdog had stayed in contention, causing problems for Buatsi, who utilized a tight guard to barely take the better periods.
The spectators' acceptance decreased amid regular grabbing, with the challenger going down multiple occasions during clinches.
The underdog ended stronger, but several stanzas were challenging to assess. Although, ex-champion the boxing analyst - providing analysis for Dazn - had it significantly in favor for the challenger, giving Buatsi just only one stanza.
Buatsi progresses, but with the presence of hard hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Tribute Fuels Local Rivalry Battle
In the secondary fight, Arthur defeated Bradley Rea by divided decision in a terrific all-Manchester fight to secure the European light heavyweight championship.
The venue fell silent for a extremely emotional homage prior to the bout as ten bells sounded in memory of local hero Hatton, who succumbed 46 years old in last month.
It was the initial significant broadcast fight night in the location since Hatton's death. As the final chime ended, the silence transitioned to a shout of "there's only one Ricky Hatton".
The competition inside the ropes equaled the feeling. The eventual winner was knocked down by a powerful punch directly to the face in the second round, rising shakily to his footing on the count of eight.
But the Manchester United-red shorts of Arthur soon advanced again. On the opposite side, Rea - in opposing blue - was injured soon, heavy swelling appearing under his orbital area as the pair landed hard punches.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, fought fire with fire with effective uppercuts as the action seldom decreased over 12 rounds.
Arthur barely secured the verdict with official scores of even score, 115-113 and clearer margin, but both fighters were relentless and full of heart, everything their hero the legend represented.
