British light heavyweight Buatsi secured a victory yet unimpressive debut to his career under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output likely gained him a split decision in a tight ten-round contest at the Manchester venue.
But the challenger landed significant shots, connecting with powerful individual punches in a fight where the approaches never quite clicked, with excessive holding spoiling the fight.
The scoring judges scored it 96-94 to the winner, with the final judge a even score.
"It wasn't my greatest performance but what do champions do? They succeed," the victor stated in the ringside as he was greeted with disapproval from the audience.
The British fighter got back to winning after his first professional defeat - an memorable fight with Callum Smith in last winter - to earn a 20th pro success.
Several boxing experts thought the challenger, 31, deserved the win but the contender experienced the second loss of his 28-fight career.
Buatsi Earns Victory in Uneventful Affair
Buatsi's progress has stalled in recent times through contract problems and extended periods of inactivity.
Once tipped as the rising talent of UK boxing, he now stands trying to achieve expectations - perhaps in what appears to be a last chance - under new promotional backing.
He started carefully, with both competitors willing to be aggressive in a calculated early stages.
Parker, whose sole prior loss came at super middleweight against his former opponent in two years ago after breaking his hand in the contest, was participating in his second fight at light-heavyweight.
By the middle rounds, Parker had kept it close, causing problems for the favorite, who operated with a protective stance to edge the more effective periods.
The crowd's patience decreased amid constant clinching, with the challenger slipping to the canvas several times during clinches.
The underdog closed well, but several stanzas were challenging to assess. Nevertheless, former world champion the boxing analyst - providing analysis for Dazn - had it particularly wide for the challenger, awarding Buatsi just one round.
Buatsi moves on, but with the presence of power puncher Benavidez, and Russian champion Bivol ruling the division, the path to championship success - on this evidence - still appears challenging.
Hatton Memorial Motivates Manchester Derby Contest
In the secondary fight, Arthur overcame Rea by close verdict in a excellent Manchester vs Manchester contest to capture the continental belt.
The venue became quiet for a deeply poignant homage before the fight as ten bells tolled in memory of the city's native Hatton, who succumbed 46 years old in recently.
It was the initial significant broadcast match card in the city since the passing of Hatton. As the concluding sound disappeared, the silence became a shout of "there's only one Ricky Hatton".
The action inside the ropes equaled the emotion. Arthur was floored by a significant blow directly to the face in the second round, getting up unsteadily to his footing on the eight count.
But the Manchester United-red equipment of the fighter soon pressed ahead again. Across the ring, Rea - in rival City blue - was marked up quickly, heavy swelling forming under his eye as the pair traded powerful shots.
Rea, 27, delivered effective strikes but Arthur, 34, responded in kind with effective uppercuts as the pace hardly diminished over twelve rounds.
The victor edged the decision with scoring tallies of draw, narrow lead and 115-112, but the two athletes were relentless and brave, exactly what their hero the legend represented.
