British light-heavyweight Buatsi made a winning yet disappointing debut to his career under new promoters with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a competitive ten-round bout at the boxing arena.
But the challenger found success, landing some telling clean blows in a match where the styles failed to mesh, with excessive holding disrupting the fight.
The officials had it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest performance but how do champions respond? They prevail," Buatsi said in the ringside as he was greeted with boos from the crowd.
The British fighter got back to winning after his first professional defeat - an thrilling contest with Callum Smith in last winter - to claim a 20th career victory.
Various analysts believed Parker, thirty-one, merited the win but the contender suffered the second defeat of his 28-match professional journey.
The Champion Earns Triumph in Dull Affair
His career development has stalled in recent years through contract problems and extended periods of lack of fights.
Earlier forecast as the rising talent of UK boxing, he now finds himself trying to realize his potential - perhaps in what appears to be a final roll of the dice - under new promotional backing.
He started carefully, with the two boxers willing to overcommit in a tentative initial rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in 2022 after breaking his hand mid-fight, was competing in only his second fight at light-heavyweight.
By the halfway stage, the underdog had stayed in contention, causing problems for Buatsi, who utilized a solid defense to narrowly win the more effective periods.
The crowd's patience diminished amid constant clinching, with the challenger going down various instances during clinches.
The underdog closed well, but several stanzas were hard to judge. Nevertheless, former world champion the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, giving Buatsi just a single round.
Buatsi progresses, but with the caliber of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the path to championship success - judging by this showing - still appears challenging.
Ricky Hatton Tribute Fuels Local Rivalry Contest
In the supporting bout, Arthur beat Rea by split-decision in a outstanding Manchester vs Manchester battle to capture the European light-heavyweight title.
The stadium fell silent for a extremely emotional homage before the fight as 10 bells rang in honor of Manchester's own Hatton, who succumbed 46 years old in recently.
It was the first major televised fight night in the urban center since the passing of Hatton. As the last bell ended, the stillness transitioned to a shout of "there's only one Hatton".
The fighting inside the ropes equaled the feeling. Arthur was floored by a powerful punch flush on the chin in the second round, rising shakily to his position on the referee's count.
But the traditional red equipment of Arthur soon came forward again. From the other corner, the opponent - in competitive blue - was injured soon, significant bruising developing under his face as the pair traded punishing blows.
Rea, 27, connected with strong blows but Arthur, thirty-four, matched the intensity with stinging uppercuts as the intensity rarely dropped over the full distance.
The victor barely secured the decision with official scores of 114-114, narrow lead and clearer margin, but each competitor were determined and full of heart, exactly what their hero the legend embodied.
