UK light-heavyweight Buatsi made a winning yet disappointing debut to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's work rate likely gained him a majority decision in a competitive ten-round contest at the Co-op Live Arena.
But the challenger found success, delivering effective individual punches in a fight where the approaches never quite clicked, with excessive holding disrupting the action.
The officials had it 96-94 for to the winner, with the final judge a even score.
"It wasn't my greatest showing but how do champions respond? They prevail," Buatsi said in the ring as he was greeted with disapproval from the audience.
The British fighter got back to winning after his maiden career setback - an memorable fight with Callum Smith in last winter - to claim a twentieth professional win.
Several boxing experts believed Parker, thirty-one, merited the win but the contender endured the second defeat of his 28-match professional journey.
The Champion Secures Triumph in Slow Encounter
Buatsi's progress has slowed in recent years through management issues and extended periods of lack of fights.
Previously predicted as the future of British boxing, he now finds himself trying to realize his potential - perhaps in what feels like a ultimate opportunity - under fresh management.
He started carefully, with neither fighter prepared to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after damaging his hand in the contest, was participating in his second fight at the higher weight class.
By the middle rounds, the underdog had stayed in contention, creating difficulties for the favorite, who utilized a tight guard to edge the cleaner rounds.
The spectators' acceptance diminished during regular grabbing, with the challenger slipping to the canvas various instances during grappling.
Parker ended stronger, but multiple periods were challenging to assess. Nevertheless, former world champion the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for the challenger, scoring for Buatsi just one round.
The victor progresses, but with the presence of power puncher Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - judging by this showing - still looks steep.
Hatton Memorial Motivates Manchester Derby Battle
In the co-main event, Lyndon Arthur defeated Bradley Rea by close verdict in a outstanding all-Manchester battle to capture the continental title.
The venue grew hushed for a profoundly moving homage before the fight as 10 bells sounded in memory of Manchester's own Hatton, who passed away at age 46 in recently.
It was the first major televised fight night in the urban center since Hatton's passing. As the concluding sound ended, the quiet transitioned to a chant of "there's only one Ricky Hatton".
The action inside the ropes matched the feeling. The eventual winner was floored by a significant blow squarely on the jaw in the initial stage, getting up unsteadily to his position on the referee's count.
But the red-colored equipment of the fighter soon advanced again. Across the ring, Rea - in opposing blue - was injured early, significant bruising forming under his orbital area as the pair exchanged powerful shots.
The challenger, 27, connected with strong blows but the champion, thirty-four, responded in kind with effective uppercuts as the action rarely dropped over the full distance.
Arthur narrowly won the decision with judges scorecards of draw, 115-113 and wider gap, but each competitor were persistent and courageous, all the qualities their idol the legend embodied.
