British light heavyweight Buatsi secured a victory yet disappointing debut to his career under new promoters with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a tight 10-round bout at the boxing arena.
But Parker found success, connecting with powerful clean blows in a match where the techniques failed to mesh, with excessive holding disrupting the fight.
The officials judged it 96-94 to Buatsi, with the third a 95-95.
"It wasn't my finest display but how do champions respond? They prevail," the victor commented in the ringside as he was faced negative reactions from the crowd.
The British fighter bounced back after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a twentieth professional win.
Various analysts thought the challenger, thirty-one, should have been awarded the decision but the Derbyshire fighter experienced the second setback of his 28-bout career.
Buatsi Claims Win in Dull Affair
The fighter's advancement has slowed in recent years through promotional disputes and long spells of inactivity.
Once tipped as the rising talent of the British fight scene, he now stands trying to fulfil that early promise - maybe in what feels like a final roll of the dice - under recent support.
He opened tentatively, with neither fighter prepared to overcommit in a calculated early stages.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after breaking his hand in the contest, was competing in only his second bout at light heavyweight.
By the middle rounds, the underdog had stayed in contention, making life awkward for Buatsi, who operated with a tight guard to narrowly win the cleaner rounds.
The audience's tolerance decreased amid constant clinching, with the challenger going down various instances during clinches.
Parker closed well, but several stanzas were difficult to score. Although, ex-champion the boxing analyst - commentating on the broadcast network - had it significantly in favor for Parker, giving Buatsi just one round.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Russian champion Bivol dominating the weight class, the path to championship success - on this evidence - still appears challenging.
Hatton Homage Inspires Manchester Derby Battle
In the secondary fight, Arthur overcame Rea by close verdict in a terrific Manchester vs Manchester battle to capture the continental title.
The arena grew hushed for a profoundly moving homage prior to the bout as a bell ceremony sounded in remembrance of the city's native Ricky Hatton, who died at age 46 in last month.
It was the first major televised fight night in the urban center since Hatton's passing. As the final chime faded, the silence became a shout of "there's just one Hatton".
The competition during the bout matched the emotion. Arthur was sent to the canvas by a powerful punch directly to the chin in the initial stage, standing uncertainly to his position on the count of eight.
But the Manchester United-red attire of the fighter soon pressed ahead again. Across the ring, Rea - in competitive blue - was marked up early, significant bruising forming under his orbital area as the duo exchanged powerful shots.
Rea, twenty-seven, delivered effective strikes but Arthur, 34, responded in kind with effective uppercuts as the intensity rarely dropped over 12 rounds.
Arthur barely secured the decision with judges scorecards of 114-114, 115-113 and 115-112, but both fighters were persistent and brave, exactly what their idol the legend represented.
