UK light heavyweight Buatsi secured a victory 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 judges' verdict in a close ten-round contest at the boxing arena.
But the challenger landed significant shots, delivering effective single shots in a fight where the approaches didn't complement each other, with frequent clinching spoiling the contest.
The scoring judges judged it 96-94 in favor to Buatsi, with the third a even score.
"It wasn't my finest showing but what do champions do? They win," the victor commented in the ring as he was faced disapproval from the crowd.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in last winter - to earn a 20th pro success.
Some ringside observers thought Parker, thirty-one, should have been awarded the win but the contender experienced the second setback of his 28-match professional journey.
The Champion Earns Win in Uneventful Encounter
His career development has slowed in recent years through promotional disputes and long spells of inactivity.
Previously predicted as the future of the British fight scene, he now stands trying to achieve expectations - maybe in what seems like a ultimate opportunity - under fresh management.
He opened tentatively, with the two boxers willing to be aggressive in a cagey early stages.
The challenger, whose only previous defeat came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was participating in his second fight at light-heavyweight.
By the fight's midpoint, the underdog had stayed in contention, causing problems for Buatsi, who utilized a protective stance to narrowly win the cleaner rounds.
The crowd's patience decreased because of constant clinching, with the challenger falling to the floor several times during close exchanges.
Parker finished the stronger, but many rounds were challenging to assess. Although, ex-champion Carl Frampton - working with the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just one round.
Buatsi moves on, but with the likes of power puncher David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still seems difficult.
Ricky Hatton Tribute Fuels Manchester Derby Contest
In the co-main event, Lyndon Arthur beat Bradley Rea by split-decision in a terrific Manchester vs Manchester contest to win the continental belt.
The arena fell silent for a deeply poignant tribute prior to the bout as ten bells tolled in honor of the city's native Ricky Hatton, who succumbed 46 years old in recently.
It was the premier televised match card in the location since Hatton's passing. As the concluding sound faded, the silence became a shout of "only one Hatton".
The action during the bout equaled the emotion. The eventual winner was knocked down by a significant blow squarely on the chin in the second round, rising shakily to his feet on the count of eight.
But the red-colored equipment of Arthur soon pressed ahead again. On the opposite side, Rea - in opposing blue - was injured early, noticeable damage developing under his orbital area as the fighters traded hard punches.
Rea, 27, connected with strong blows but the champion, thirty-four, matched the intensity with powerful upward punches as the intensity rarely dropped over twelve rounds.
The victor narrowly won the decision with judges scorecards of even score, 115-113 and 115-112, but each competitor were persistent and full of heart, everything their idol the legend represented.
