UK light heavyweight Buatsi made a winning yet unimpressive beginning to life 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 judges' verdict in a competitive 10-round contest at the Manchester venue.
But Parker landed significant shots, landing some telling individual punches in a fight where the approaches never quite clicked, with excessive holding spoiling the action.
Two judges judged it 96-94 to Buatsi, with the third a 95-95 draw.
"It wasn't my best showing but what do champions do? They prevail," Buatsi commented in the arena as he was met by negative reactions from the spectators.
The Londoner bounced back after his first professional defeat - an thrilling contest with Callum Smith in last winter - to secure a 20th pro success.
Various analysts believed Parker, thirty-one, merited the win but the Derbyshire fighter experienced the second setback of his 28-bout career.
The Champion Claims Win in Uneventful Affair
His career development has stalled in recent years through promotional disputes and considerable time of inactivity.
Previously predicted as the future of the British fight scene, he now finds himself trying to fulfil that early promise - perhaps in what feels like a final roll of the dice - under fresh management.
He started carefully, with both competitors ready to be aggressive in a calculated opening few rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after damaging his hand in the contest, was competing in only his second bout at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, making life awkward for the favorite, who operated with a solid defense to barely take the cleaner stanzas.
The crowd's patience decreased during regular grabbing, with the challenger slipping to the canvas various instances during close exchanges.
Parker closed well, but multiple periods were challenging to assess. However, former world champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, awarding Buatsi just only one stanza.
The victor advances, but with the presence of hard hitter Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - on this evidence - still seems difficult.
Hatton Tribute Motivates Local Rivalry Fight
In the secondary fight, Arthur overcame Rea by split-decision in a terrific all-Manchester battle to secure the European light-heavyweight belt.
The arena became quiet for a extremely emotional homage prior to the bout as a bell ceremony rang in remembrance of Manchester's own Hatton, who passed away at age 46 in recently.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the last bell faded, the stillness gave way to a roar of "only one Hatton".
The action within the ring equaled the emotion. The eventual winner was floored by a powerful punch squarely on the face in the initial stage, getting up unsteadily to his footing on the count of eight.
But the Manchester United-red attire of the fighter soon came forward again. From the other corner, the opponent - in competitive blue - was damaged early, significant bruising appearing under his eye as the pair landed powerful shots.
The challenger, twenty-seven, landed power punches but the champion, 34, responded in kind with stinging uppercuts as the action hardly diminished over the full distance.
Arthur barely secured the result with official scores of 114-114, narrow lead and wider gap, but each competitor were relentless and brave, exactly what their hero the legend represented.
