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 bronze medallist's activity level seemingly secured him a majority decision in a tight 10-round bout at the boxing arena.
But Parker had his moments, landing some telling clean blows in a contest where the approaches never quite clicked, with constant grabbing disrupting the action.
The scoring judges had it 96-94 to the winner, with the remaining official a even score.
"It wasn't my greatest performance but how do champions respond? They succeed," the victor commented in the arena as he was greeted with negative reactions from the crowd.
The Londoner returned to winning ways after his maiden career setback - an memorable fight with Callum Smith in last winter - to claim a 20th pro success.
Various analysts believed the challenger, thirty-one, deserved the win but the Derbyshire fighter endured the second setback of his 28-match career.
The Champion Claims Triumph in Dull Match
Buatsi's progress has slowed in recent years through promotional disputes and extended periods of lack of fights.
Earlier forecast as the future of British boxing, he now stands trying to fulfil that early promise - possibly in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors prepared to overcommit in a tentative initial rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in two years ago after breaking his hand during the bout, was making just his second fight at the higher weight class.
By the halfway stage, Parker had made it competitive, making life awkward for the favorite, who operated with a tight guard to narrowly win the better periods.
The crowd's patience diminished because of frequent holding, with the challenger going down several times during clinches.
Parker closed well, but many rounds were hard to judge. Nevertheless, former world champion Carl Frampton - providing analysis for the broadcast network - had it particularly wide for Parker, awarding Buatsi just a single round.
The victor advances, but with the likes of heavy hitter Benavidez, and Russian champion Bivol ruling the division, the path to championship success - on this evidence - still looks steep.
Ricky Hatton Tribute Motivates Local Rivalry Battle
In the supporting bout, Arthur defeated Bradley Rea by split-decision in a outstanding all-Manchester fight to secure the continental title.
The stadium grew hushed for a profoundly moving memorial ahead of the contest as ten bells tolled in remembrance of the city's native Ricky Hatton, who succumbed at age 46 in recently.
It was the premier televised boxing event in the city since Hatton's passing. As the final chime disappeared, the quiet gave way to a roar of "there's only one Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was knocked down by a significant blow directly to the jaw in the second round, getting up unsteadily to his feet on the count of eight.
But the traditional red shorts of Arthur soon advanced again. From the other corner, Rea - in opposing blue - was injured soon, significant bruising appearing under his orbital area as the duo landed punishing blows.
Rea, 27, delivered effective strikes but Arthur, 34, matched the intensity with stinging uppercuts as the intensity seldom decreased over 12 rounds.
Arthur barely secured the verdict with scoring tallies of draw, 115-113 and wider gap, but the two athletes were determined and full of heart, everything their idol the legend represented.
