British light heavyweight Buatsi earned a win yet unimpressive beginning to life under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output appeared to earn him a split decision in a competitive 10-round contest at the Co-op Live Arena.
But the challenger landed significant shots, landing some telling individual punches in a match where the styles failed to mesh, with constant grabbing disrupting the action.
Two judges judged it 96-94 for to the winner, with the third a even score.
"It wasn't my best performance but what do champions do? They prevail," the victor said in the ring as he was greeted with disapproval from the audience.
The Londoner got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to claim a twentieth professional win.
Some ringside observers believed the challenger, thirty-one, should have been awarded the win but the contender suffered the second loss of his 28-bout career.
The Champion Secures Win in Uneventful Match
His career development has stalled in recent years through promotional disputes and extended periods of inactivity.
Earlier forecast as the next star of UK boxing, he now is positioned trying to achieve expectations - possibly in what feels like a ultimate opportunity - under fresh management.
He started carefully, with both competitors prepared to overcommit in a calculated initial rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in two years ago after breaking his hand mid-fight, was competing in only his second appearance at light heavyweight.
By the halfway stage, Parker had stayed in contention, making life awkward for Buatsi, who worked behind a tight guard to barely take the more effective stanzas.
The crowd's patience wore thin during constant clinching, with Parker going down multiple occasions during clinches.
The underdog closed well, but many rounds were challenging to assess. However, previous titleholder the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, giving Buatsi just one round.
The victor progresses, but with the caliber of power puncher Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - on this evidence - still looks steep.
Hatton Homage Motivates Local Rivalry Fight
In the secondary fight, Arthur defeated Bradley Rea by divided decision in a terrific local rivalry contest to win the continental title.
The arena became quiet for a extremely emotional tribute ahead of the contest as 10 bells tolled in honor of the city's native Hatton, who died aged 46 in September.
It was the first major televised match card in the city since the passing of Hatton. As the concluding sound ended, the stillness gave way to a shout of "there's just one Ricky Hatton".
The fighting within the ring reflected the feeling. The eventual winner was knocked down by a significant blow flush on the face in the initial stage, getting up unsteadily to his feet on the eight count.
But the traditional red attire of the fighter soon came forward again. From the other corner, Rea - in rival City blue - was marked up soon, heavy swelling developing under his eye as the pair exchanged powerful shots.
The challenger, 27, connected with strong blows but Arthur, thirty-four, matched the intensity with stinging uppercuts as the pace seldom decreased over twelve rounds.
The victor narrowly won the result with scoring tallies of even score, 115-113 and wider gap, but each competitor were persistent and brave, all the qualities their hero Hatton represented.
