British light heavyweight Buatsi secured a victory yet unimpressive beginning to his career under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output appeared to earn him a majority decision in a competitive 10-round fight at the Manchester venue.
But the challenger landed significant shots, connecting with powerful individual punches in a contest where the approaches failed to mesh, with frequent clinching marring the contest.
Two judges scored it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my greatest performance but what do champions do? They win," Buatsi stated in the arena as he was met by negative reactions from the crowd.
The Londoner got back to winning after his initial pro loss - an memorable fight with Callum Smith in February - to earn a twentieth professional win.
Some ringside observers believed Parker, thirty-one, deserved the victory but the contender suffered the second loss of his 28-bout professional journey.
The Champion Earns Victory in Uneventful Encounter
The fighter's advancement has stalled in recent times through promotional disputes and extended periods of inactivity.
Once tipped as the next star of the British fight scene, he now stands trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under recent support.
He started carefully, with neither fighter ready to overcommit in a cagey initial rounds.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after suffering a hand injury mid-fight, was participating in his second fight at light-heavyweight.
By the halfway stage, the underdog had stayed in contention, making life awkward for the favorite, who worked behind a tight guard to narrowly win the cleaner periods.
The crowd's patience wore thin because of regular grabbing, with Parker slipping to the canvas various instances during grappling.
The underdog closed well, but multiple periods were challenging to assess. Although, previous titleholder Carl Frampton - working with Dazn - had it strongly leaning for Parker, giving Buatsi just one round.
Buatsi advances, but with the presence of power puncher Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Tribute Motivates All-Manchester Fight
In the supporting bout, Arthur beat Bradley Rea by split-decision in a outstanding local rivalry battle to capture the continental belt.
The venue grew hushed for a extremely emotional homage before the fight as a bell ceremony sounded in honor of Manchester's own Ricky Hatton, who died 46 years old in September.
It was the premier televised boxing event in the urban center since Hatton's death. As the last bell disappeared, the silence gave way to a roar of "there's just one Ricky Hatton".
The action inside the ropes matched the feeling. Arthur was sent to the canvas by a significant blow directly to the chin in the early round, rising shakily to his footing on the count of eight.
But the Manchester United-red shorts of the fighter soon came forward again. From the other corner, Rea - in competitive blue - was injured soon, noticeable damage forming under his orbital area as the duo landed powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with stinging uppercuts as the pace seldom decreased over 12 rounds.
The victor edged the verdict with scoring tallies of draw, close margin and wider gap, but each competitor were determined and full of heart, exactly what their hero the legend represented.
