UK light-heavyweight Buatsi earned a win yet disappointing start to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a close ten-round bout at the boxing arena.
But the challenger found success, landing some telling single shots in a match where the techniques failed to mesh, with constant grabbing disrupting the action.
The scoring judges judged it 96-94 for to Buatsi, with the third a even score.
"It wasn't my greatest performance but what defines champions? They succeed," the victor commented in the arena as he was greeted with negative reactions from the crowd.
The Londoner returned to winning ways after his first professional defeat - an epic battle with Callum Smith in February - to earn a twentieth professional win.
Several boxing experts felt Parker, 31, merited the victory but the contender experienced the second defeat of his 28-fight professional journey.
Buatsi Earns Victory in Uneventful Affair
Buatsi's progress has slowed in recent times through management issues and considerable time of lack of fights.
Once tipped as the future of the British fight scene, he now finds himself trying to fulfil that early promise - perhaps in what appears to be a last chance - under new promotional backing.
He began cautiously, with the two boxers prepared to take risks in a cagey initial rounds.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in 2022 after suffering a hand injury during the bout, was participating in his second bout at the higher weight class.
By the middle rounds, Parker had stayed in contention, creating difficulties for Buatsi, who utilized a protective stance to barely take the more effective rounds.
The audience's tolerance decreased amid regular grabbing, with Parker slipping to the canvas multiple occasions during grappling.
Parker ended stronger, but multiple periods were difficult to score. Although, ex-champion the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, giving Buatsi just only one stanza.
The victor advances, but with the caliber of heavy hitter Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the path to championship success - on this evidence - still appears challenging.
Hatton Tribute Fuels All-Manchester Battle
In the co-main event, Lyndon Arthur overcame Rea by split-decision in a outstanding Manchester vs Manchester fight to capture the European light heavyweight title.
The arena fell silent for a extremely emotional memorial before the fight as 10 bells sounded in honor of the city's native Hatton, who passed away 46 years old in last month.
It was the first major televised fight night in the location since Hatton's passing. As the concluding sound disappeared, the quiet gave way to a chant of "only one Ricky Hatton".
The fighting inside the ropes equaled the sentiment. The eventual winner was knocked down by a left hook flush on the jaw in the second round, getting up unsteadily to his feet on the count of eight.
But the red-colored equipment of the fighter soon pressed ahead again. Across the ring, the opponent - in opposing blue - was damaged early, heavy swelling appearing under his eye as the fighters traded hard punches.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, matched the intensity with effective uppercuts as the action seldom decreased over 12 rounds.
The victor narrowly won the verdict with judges scorecards of draw, narrow lead and wider gap, but both fighters were relentless and courageous, everything their idol Hatton stood for.
