British light-heavyweight Buatsi secured a victory yet unimpressive debut to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful single shots in a fight where the approaches failed to mesh, with excessive holding marring the action.
The officials scored it 96-94 to Buatsi, with the final judge a 95-95.
"It wasn't my greatest display but how do champions respond? They win," the victor commented in the arena as he was met by negative reactions from the spectators.
The British fighter got back to winning after his first professional defeat - an memorable fight with Callum Smith in last winter - to claim a 20th career victory.
Various analysts felt the challenger, thirty-one, deserved the decision but the contender experienced the second setback of his 28-fight career.
Buatsi Claims Victory in Dull Affair
His career development has slowed in the past few years through contract problems and considerable time of inactivity.
Once tipped as the future of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what appears to be a last chance - under recent support.
He started carefully, with both competitors prepared to overcommit in a calculated opening few rounds.
Parker, whose single earlier setback came at the lower weight class against his former opponent in two years ago after breaking his hand in the contest, was participating in his second bout at light heavyweight.
By the fight's midpoint, the underdog had made it competitive, making life awkward for the favorite, who worked behind a tight guard to barely take the cleaner stanzas.
The crowd's patience wore thin because of constant clinching, with the challenger going down various instances during grappling.
Parker finished the stronger, but multiple periods were hard to judge. Nevertheless, ex-champion Carl Frampton - providing analysis for the broadcast network - had it particularly wide for the challenger, giving Buatsi just a single round.
Buatsi progresses, but with the presence of heavy hitter David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still looks steep.
Hatton Homage Fuels All-Manchester Contest
In the co-main event, Arthur defeated Bradley Rea by split-decision in a excellent Manchester vs Manchester contest to capture the continental belt.
The stadium fell silent for a extremely emotional tribute before the fight as 10 bells sounded in memory of the city's native Ricky Hatton, who died at age 46 in September.
It was the initial significant broadcast boxing event in the location since Hatton's death. As the concluding sound disappeared, the stillness gave way to a roar of "there's just one Ricky Hatton".
The action inside the ropes equaled the feeling. Arthur was knocked down by a powerful punch squarely on the face in the second round, rising shakily to his feet on the referee's count.
But the red-colored equipment of Arthur soon came forward again. Across the ring, the opponent - in opposing blue - was injured early, heavy swelling developing under his eye as the pair landed hard punches.
Rea, 27, connected with strong blows but Arthur, 34, fought fire with fire with effective uppercuts as the action rarely dropped over the full distance.
Arthur barely secured the verdict with scoring tallies of even score, 115-113 and 115-112, but each competitor were persistent and full of heart, exactly what their hero Hatton represented.
