UK light-heavyweight Buatsi earned a win yet underwhelming debut to life under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a tight ten-round bout at the Manchester venue.
But Parker landed significant shots, delivering effective single shots in a match where the approaches failed to mesh, with constant grabbing marring the contest.
The officials judged it 96-94 to the winner, with the third a 95-95.
"It wasn't my finest display but what do champions do? They win," Buatsi stated in the arena as he was greeted with boos from the crowd.
The British fighter bounced back after his initial pro loss - an thrilling contest with Callum Smith in last winter - to secure a 20th pro success.
Various analysts believed the challenger, 31, merited the win but the contender endured the second setback of his 28-fight career.
The Champion Claims Victory in Uneventful Encounter
The fighter's advancement has stalled in recent times through management issues and long spells of inactivity.
Once tipped as the future of UK boxing, he now is positioned trying to realize his potential - maybe in what seems like a last chance - under recent support.
He opened tentatively, with both competitors ready to overcommit in a calculated initial rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after suffering a hand injury mid-fight, was participating in his second fight at the higher weight class.
By the middle rounds, Parker had stayed in contention, causing problems for Buatsi, who utilized a tight guard to edge the better stanzas.
The crowd's patience diminished because of frequent holding, with Parker falling to the floor multiple occasions during clinches.
The underdog ended stronger, but multiple periods were challenging to assess. Nevertheless, ex-champion the boxing analyst - commentating on the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just a single round.
The victor moves on, but with the likes of heavy hitter David Benavidez, and Russian star Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Tribute Inspires Local Rivalry Battle
In the co-main event, Lyndon Arthur beat Rea by divided decision in a outstanding all-Manchester battle to capture the European light heavyweight title.
The venue became quiet for a extremely emotional homage before the fight as ten bells tolled in memory of Manchester's own Hatton, who passed away at age 46 in recently.
It was the premier televised boxing event in the urban center since Hatton's passing. As the concluding sound disappeared, the quiet transitioned to a roar of "there's only one Ricky Hatton".
The action within the ring equaled the emotion. Arthur was knocked down by a significant blow flush on the jaw in the initial stage, rising shakily to his feet on the eight count.
But the traditional red equipment of Arthur soon advanced again. On the opposite side, the opponent - in competitive blue - was marked up early, noticeable damage forming under his eye as the pair landed powerful shots.
Rea, 27, connected with strong blows but the champion, 34, fought fire with fire with effective uppercuts as the intensity hardly diminished over the full distance.
Arthur narrowly won the result with judges scorecards of draw, narrow lead and 115-112, but the two athletes were persistent and brave, everything their hero the legend embodied.
