British light-heavyweight Buatsi secured a victory yet disappointing beginning to his career under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's work rate likely gained him a split decision in a tight ten-round contest at the Co-op Live Arena.
But Parker found success, connecting with powerful individual punches in a fight where the styles didn't complement each other, with excessive holding disrupting the action.
Two judges had it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest showing but what do champions do? They prevail," the victor commented in the arena as he was met by boos from the spectators.
The British fighter returned to winning ways after his first professional defeat - an epic battle with Callum Smith in February - to claim a twentieth professional win.
Various analysts felt the challenger, thirty-one, merited the win but the Derbyshire fighter experienced the second defeat of his 28-fight career.
Buatsi Claims Triumph in Dull Encounter
Buatsi's progress has stalled in recent times through contract problems and extended periods of inactivity.
Previously predicted as the future of British boxing, he now finds himself trying to realize his potential - possibly in what seems like a last chance - under recent support.
He began cautiously, with neither fighter willing to overcommit in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in 2022 after damaging his hand during the bout, was making just his second appearance at the higher weight class.
By the fight's midpoint, Parker had kept it close, causing problems for the favorite, who operated with a protective stance to barely take the cleaner periods.
The crowd's patience diminished during regular grabbing, with the challenger going down several times during close exchanges.
Parker closed well, but multiple periods were difficult to score. However, ex-champion Carl Frampton - working with Dazn - had it significantly in favor for Parker, scoring for Buatsi just one round.
Buatsi progresses, but with the likes of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the journey to titles - on this evidence - still seems difficult.
Hatton Homage Fuels Manchester Derby Contest
In the secondary fight, Lyndon Arthur beat Bradley Rea by close verdict in a terrific all-Manchester fight to capture the European light-heavyweight belt.
The venue became quiet for a deeply poignant memorial before the fight as a bell ceremony tolled in honor of the city's native Hatton, who succumbed aged 46 in recently.
It was the initial significant broadcast fight night in the city since Hatton's death. As the concluding sound faded, the silence became a roar of "only one Hatton".
The action inside the ropes matched the sentiment. Arthur was knocked down by a powerful punch squarely on the face in the initial stage, getting up unsteadily to his footing on the referee's count.
But the Manchester United-red shorts of the fighter soon advanced again. From the other corner, Rea - in competitive blue - was damaged early, heavy swelling appearing under his orbital area as the pair exchanged hard punches.
The challenger, 27, landed power punches but the champion, 34, fought fire with fire with effective uppercuts as the action hardly diminished over the full distance.
Arthur narrowly won the result with official scores of 114-114, close margin and clearer margin, but each competitor were relentless and brave, exactly what their idol the legend represented.
