British light-heavyweight Buatsi made a winning yet disappointing debut to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a judges' verdict in a tight 10-round contest at the boxing arena.
But Parker had his moments, landing some telling single shots in a contest where the styles didn't complement each other, with frequent clinching marring the fight.
Two judges judged it 96-94 to Buatsi, with the third a 95-95.
"It wasn't my greatest display but what defines champions? They prevail," Buatsi stated in the arena as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an epic battle with his previous opponent in February - to earn a 20th pro success.
Some ringside observers believed Parker, thirty-one, merited the victory but the British boxer endured the second loss of his 28-fight career.
Buatsi Secures Victory in Uneventful Affair
His career development has stalled in the past few years through promotional disputes and long spells of lack of fights.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to achieve expectations - perhaps in what feels like a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter prepared to be aggressive in a calculated early stages.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after breaking his hand in the contest, was making just his second bout at the higher weight class.
By the middle rounds, Parker had stayed in contention, creating difficulties for Buatsi, who operated with a protective stance to barely take the better stanzas.
The crowd's patience diminished because of frequent holding, with Parker going down multiple occasions during grappling.
The underdog closed well, but multiple periods were difficult to score. However, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for the challenger, scoring for Buatsi just a single round.
Buatsi progresses, but with the likes of hard hitter Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - on this evidence - still looks steep.
Ricky Hatton Homage Motivates Manchester Derby Fight
In the co-main event, Arthur beat Bradley Rea by close verdict in a outstanding all-Manchester battle to secure the continental belt.
The arena became quiet for a deeply poignant memorial prior to the bout as a bell ceremony rang in memory of local hero Ricky Hatton, who succumbed aged 46 in recently.
It was the premier televised boxing event in the location since Hatton's passing. As the final chime disappeared, the quiet became a shout of "there's just one Hatton".
The competition inside the ropes reflected the feeling. Arthur was floored by a significant blow flush on the jaw in the second round, getting up unsteadily to his footing on the count of eight.
But the Manchester United-red equipment of the fighter soon advanced again. On the opposite side, the opponent - in rival City blue - was injured quickly, noticeable damage forming under his eye as the pair traded powerful shots.
Rea, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with effective uppercuts as the action rarely dropped over twelve rounds.
The victor edged the result with scoring tallies of even score, close margin and clearer margin, but each competitor were relentless and brave, everything their idol Hatton represented.
