British light heavyweight Buatsi secured a victory yet underwhelming start to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a majority decision in a competitive ten-round contest at the Co-op Live Arena.
But Parker found success, connecting with powerful individual punches in a match where the techniques never quite clicked, with constant grabbing spoiling the action.
The scoring judges judged it 96-94 for to the winner, with the remaining official a 95-95.
"It wasn't my best performance but what do champions do? They succeed," Buatsi commented in the ringside as he was met by boos from the audience.
The British fighter returned to winning ways after his first professional defeat - an epic battle with Callum Smith in last winter - to claim a 20th pro success.
Various analysts felt the challenger, 31, merited the decision but the Derbyshire fighter experienced the second loss of his 28-bout professional journey.
The Champion Secures Win in Dull Encounter
Buatsi's progress has plateaued in the past few years through contract problems and considerable time of inactivity.
Once tipped as the future of British boxing, he now is positioned trying to fulfil that early promise - perhaps in what appears to be a final roll of the dice - under new promotional backing.
He started carefully, with the two boxers willing to overcommit in a cagey early stages.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was making just his second bout at light heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for Buatsi, who worked behind a protective stance to narrowly win the cleaner rounds.
The crowd's patience wore thin because of frequent holding, with Parker slipping to the canvas multiple occasions during clinches.
The underdog finished the stronger, but multiple periods were challenging to assess. Although, previous titleholder the boxing analyst - working with the broadcast network - had it strongly leaning for the challenger, giving Buatsi just one round.
Buatsi progresses, but with the likes of hard hitter Benavidez, and Russian star Bivol dominating the weight class, the journey to titles - based on this performance - still looks steep.
Ricky Hatton Homage Inspires All-Manchester Fight
In the supporting bout, Lyndon Arthur defeated Rea by close verdict in a outstanding Manchester vs Manchester contest to win the European light-heavyweight title.
The venue grew hushed for a profoundly moving tribute before the fight as a bell ceremony sounded in honor of local hero Ricky Hatton, who succumbed 46 years old in recently.
It was the initial significant broadcast match card in the city since the passing of Hatton. As the final chime faded, the silence gave way to a roar of "only one Hatton".
The action within the ring reflected the emotion. The eventual winner was sent to the canvas by a significant blow flush on the face in the second round, rising shakily to his position on the referee's count.
But the traditional red attire of Arthur soon pressed ahead again. On the opposite side, Rea - in competitive blue - was damaged quickly, noticeable damage appearing under his orbital area as the pair traded hard punches.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with powerful upward punches as the pace hardly diminished over twelve rounds.
The victor narrowly won the verdict with judges scorecards of draw, 115-113 and clearer margin, but each competitor were persistent and full of heart, all the qualities their hero the legend represented.
