UK light-heavyweight Buatsi earned a win 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 majority decision in a tight ten-round contest at the Co-op Live Arena.
But Parker had his moments, connecting with powerful single shots in a contest where the styles failed to mesh, with frequent clinching marring the fight.
Two judges judged it 96-94 to the winner, with the final judge a 95-95.
"It wasn't my finest performance but how do champions respond? They win," Buatsi stated in the ringside as he was met by disapproval from the crowd.
The British fighter returned to winning ways after his maiden career setback - an thrilling contest with Callum Smith in February - to secure a 20th career victory.
Various analysts felt Parker, thirty-one, deserved the victory but the Derbyshire fighter endured the second loss of his 28-match career.
The Champion Claims Triumph in Uneventful Encounter
His career development has slowed in recent times through management issues and extended periods of inactivity.
Earlier forecast as the rising talent of UK boxing, he now is positioned trying to fulfil that early promise - maybe in what feels like a ultimate opportunity - under fresh management.
He started carefully, with the two boxers ready to be aggressive in a tentative initial rounds.
The challenger, whose only previous defeat came at super middleweight against John Ryder in 2022 after breaking his hand during the bout, was competing in only his second appearance at the higher weight class.
By the middle rounds, Parker had stayed in contention, causing problems for the favorite, who operated with a tight guard to edge the better stanzas.
The crowd's patience wore thin amid constant clinching, with Parker falling to the floor several times during close exchanges.
Parker ended stronger, but multiple periods were hard to judge. Nevertheless, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
The victor progresses, but with the presence of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the road to world glory - judging by this showing - still looks steep.
Hatton Tribute Motivates All-Manchester Battle
In the co-main event, Lyndon Arthur overcame Bradley Rea by divided decision in a terrific local rivalry battle to secure the European light-heavyweight title.
The stadium became quiet for a deeply poignant memorial before the fight as 10 bells rang in memory of Manchester's own Hatton, who succumbed at age 46 in recently.
It was the initial significant broadcast match card in the urban center since Hatton's passing. As the concluding sound disappeared, the silence transitioned to a chant of "there's just one Ricky Hatton".
The action inside the ropes matched the feeling. Arthur was floored by a left hook flush on the face in the second round, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of Arthur soon came forward again. Across the ring, the opponent - in competitive blue - was injured soon, significant bruising appearing under his face as the fighters landed hard punches.
Rea, 27, connected with strong blows but Arthur, 34, fought fire with fire with stinging uppercuts as the intensity rarely dropped over 12 rounds.
The victor edged the verdict with official scores of draw, close margin and 115-112, but each competitor were persistent and full of heart, exactly what their idol the legend stood for.
