UK light-heavyweight Buatsi secured a victory yet unimpressive debut to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a split decision in a competitive ten-round bout at the boxing arena.
But the challenger had his moments, delivering effective clean blows in a match where the techniques failed to mesh, with frequent clinching marring the action.
The scoring judges scored it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest display but what do champions do? They prevail," the victor stated in the ringside as he was met by boos from the audience.
The British fighter bounced back after his first professional defeat - an memorable fight with his previous opponent in February - to earn a twentieth professional win.
Various analysts believed the challenger, 31, merited the win but the Derbyshire fighter endured the second loss of his 28-bout career.
The Champion Earns Victory in Uneventful Encounter
The fighter's advancement has plateaued in recent years through contract problems and long spells of inactivity.
Once tipped as the next star of UK boxing, he now finds himself trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under fresh management.
He began cautiously, with the two boxers ready to take risks in a tentative initial rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand in the contest, was competing in only his second fight at light heavyweight.
By the halfway stage, Parker had stayed in contention, creating difficulties for Buatsi, who worked behind a solid defense to barely take the more effective rounds.
The crowd's patience decreased amid regular grabbing, with Parker falling to the floor multiple occasions during close exchanges.
The underdog finished the stronger, but many rounds were hard to judge. However, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for the challenger, giving Buatsi just only one stanza.
The victor progresses, but with the presence of hard hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - on this evidence - still looks steep.
Ricky Hatton Memorial Motivates All-Manchester Contest
In the secondary fight, Arthur beat Rea by split-decision in a terrific local rivalry battle to win the European light heavyweight title.
The stadium became quiet for a deeply poignant tribute before the fight as a bell ceremony tolled in memory of the city's native Hatton, who passed away at age 46 in last month.
It was the premier televised fight night in the location since the passing of Hatton. As the concluding sound faded, the silence transitioned to a shout of "there's only one Ricky Hatton".
The competition within the ring reflected the feeling. The eventual winner was knocked down by a powerful punch directly to the face in the initial stage, rising shakily to his feet on the referee's count.
But the traditional red shorts of Arthur soon pressed ahead again. From the other corner, Rea - in opposing blue - was damaged early, heavy swelling appearing under his eye as the fighters exchanged powerful shots.
The challenger, twenty-seven, landed power punches but Arthur, 34, matched the intensity with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur edged the result with scoring tallies of even score, narrow lead and 115-112, but each competitor were persistent and courageous, everything their inspiration Hatton represented.
