UK light heavyweight Buatsi secured a victory yet disappointing start to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's work rate appeared to earn him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But the challenger found success, delivering effective clean blows in a fight where the techniques never quite clicked, with frequent clinching spoiling the action.
Two judges had it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my greatest display but what defines champions? They prevail," the victor stated in the ringside as he was greeted with boos from the audience.
The Londoner returned to winning ways after his first professional defeat - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Various analysts believed the challenger, thirty-one, deserved the decision but the Derbyshire fighter suffered the second loss of his 28-bout professional journey.
Buatsi Claims Triumph in Uneventful Encounter
The fighter's advancement has plateaued in recent times through promotional disputes and extended periods of lack of fights.
Earlier forecast as the next star of UK boxing, he now stands trying to fulfil that early promise - possibly in what feels like a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter prepared to be aggressive in a calculated initial rounds.
The challenger, whose single earlier setback came at super middleweight against John Ryder in two years ago after breaking his hand mid-fight, was making just his second fight at the higher weight class.
By the middle rounds, Parker had kept it close, creating difficulties for the favorite, who operated with a solid defense to narrowly win the better stanzas.
The spectators' acceptance wore thin amid frequent holding, with Parker going down multiple occasions during close exchanges.
Parker closed well, but multiple periods were difficult to score. However, former world champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for the challenger, scoring for Buatsi just only one stanza.
Buatsi moves on, but with the caliber of heavy hitter David Benavidez, and Russian champion Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Hatton Homage Inspires Manchester Derby Contest
In the supporting bout, Arthur overcame Bradley Rea by divided decision in a outstanding all-Manchester battle to secure the European light heavyweight belt.
The stadium became quiet for a extremely emotional memorial ahead of the contest as ten bells rang in remembrance of local hero Hatton, who died aged 46 in recently.
It was the first major televised fight night in the city since Hatton's death. As the concluding sound faded, the stillness gave way to a roar of "there's only one Hatton".
The fighting during the bout reflected the feeling. The eventual winner was sent to the canvas by a left hook flush on the jaw in the initial stage, rising shakily to his position on the referee's count.
But the Manchester United-red equipment of Arthur soon advanced again. Across the ring, Rea - in competitive blue - was damaged soon, noticeable damage forming under his orbital area as the duo traded hard punches.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with effective uppercuts as the intensity seldom decreased over 12 rounds.
The victor barely secured the verdict with scoring tallies of 114-114, narrow lead and clearer margin, but the two athletes were relentless and brave, everything their hero Hatton represented.
