British light heavyweight Buatsi earned a win yet unimpressive debut to life under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a tight 10-round bout at the boxing arena.
But the challenger had his moments, delivering effective single shots in a contest where the approaches never quite clicked, with excessive holding spoiling the contest.
Two judges had it 96-94 for to the winner, with the third a 95-95.
"It wasn't my best showing but what defines champions? They win," the victor stated in the ringside as he was faced disapproval from the crowd.
The British fighter bounced back after his initial pro loss - an thrilling contest with his previous opponent in last winter - to secure a 20th pro success.
Various analysts felt the challenger, 31, deserved the win but the British boxer endured the second loss of his 28-bout professional journey.
The Champion Secures Triumph in Slow Match
Buatsi's progress has slowed in recent years through promotional disputes and long spells of lack of fights.
Previously predicted as the future of UK boxing, he now finds himself trying to realize his potential - maybe in what appears to be a last chance - under recent support.
He began cautiously, with both competitors ready to take risks in a tentative initial rounds.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago after suffering a hand injury during the bout, was making just his second appearance at the higher weight class.
By the fight's midpoint, the underdog had stayed in contention, making life awkward for the favorite, who worked behind a tight guard to edge the cleaner stanzas.
The audience's tolerance decreased because of frequent holding, with Parker falling to the floor various instances during clinches.
Parker finished the stronger, but multiple periods were hard to judge. However, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
Buatsi moves on, but with the presence of hard hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - based on this performance - still seems difficult.
Ricky Hatton Tribute Inspires Manchester Derby Battle
In the co-main event, Lyndon Arthur overcame Bradley Rea by split-decision in a terrific Manchester vs Manchester battle to capture the continental title.
The arena grew hushed for a deeply poignant homage ahead of the contest as a bell ceremony tolled in remembrance of the city's native Ricky Hatton, who died aged 46 in last month.
It was the premier televised fight night in the urban center since Hatton's passing. As the last bell faded, the silence became a roar of "there's just one Ricky Hatton".
The action inside the ropes matched the sentiment. Arthur was sent to the canvas by a significant blow flush on the chin in the second round, getting up unsteadily to his position on the eight count.
But the Manchester United-red shorts of Arthur soon came forward again. Across the ring, Rea - in opposing blue - was injured quickly, noticeable damage forming under his face as the fighters landed punishing blows.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with powerful upward punches as the action hardly diminished over the full distance.
Arthur narrowly won the decision with judges scorecards of draw, narrow lead and wider gap, but the two athletes were relentless and courageous, exactly what their idol Hatton represented.
