British light-heavyweight Buatsi earned a win yet unimpressive debut to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a majority decision in a competitive ten-round fight at the boxing arena.
But Parker landed significant shots, landing some telling clean blows in a match where the approaches failed to mesh, with frequent clinching marring the contest.
The scoring judges scored it 96-94 in favor to Buatsi, with the third a 95-95 draw.
"It wasn't my best showing but what do champions do? They prevail," the victor said in the arena as he was greeted with boos from the crowd.
The Londoner bounced back after his first professional defeat - an thrilling contest with Callum Smith in last winter - to earn a twentieth professional win.
Some ringside observers felt Parker, thirty-one, should have been awarded the victory but the contender experienced the second loss of his 28-fight professional journey.
The Champion Claims Triumph in Uneventful Affair
His career development has stalled in the past few years through management issues and considerable time of inactivity.
Earlier forecast as the future of British boxing, he now finds himself trying to fulfil that early promise - possibly in what feels like a last chance - under new promotional backing.
He opened tentatively, with neither fighter prepared to overcommit in a tentative 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 participating in his second fight at the higher weight class.
By the middle rounds, Parker had kept it close, making life awkward for the favorite, who worked behind a solid defense to barely take the more effective rounds.
The crowd's patience wore thin amid frequent holding, with the challenger slipping to the canvas various instances during clinches.
The underdog ended stronger, but multiple periods were difficult to score. Nevertheless, ex-champion the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, giving Buatsi just one round.
The victor moves on, but with the presence of heavy hitter David Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - on this evidence - still appears challenging.
Hatton Homage Fuels All-Manchester Fight
In the supporting bout, Arthur beat Rea by split-decision in a outstanding all-Manchester contest to secure the European light heavyweight title.
The stadium became quiet for a extremely emotional homage ahead of the contest as 10 bells rang in memory of the city's native Hatton, who succumbed at age 46 in recently.
It was the first major televised fight night in the city since the passing of Hatton. As the last bell faded, the silence transitioned to a roar of "there's only one Hatton".
The fighting within the ring matched the sentiment. The eventual winner was floored by a significant blow flush on the jaw in the initial stage, rising shakily to his position on the referee's count.
But the traditional red equipment of the fighter soon advanced again. Across the ring, Rea - in opposing blue - was marked up soon, significant bruising appearing under his eye as the fighters traded powerful shots.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, responded in kind with stinging uppercuts as the action seldom decreased over the full distance.
Arthur edged the verdict with official scores of even score, 115-113 and wider gap, but the two athletes were persistent and brave, exactly what their inspiration the legend embodied.
