UK light-heavyweight Buatsi earned a win yet underwhelming beginning to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a judges' verdict in a tight 10-round fight at the Manchester venue.
But Parker landed significant shots, connecting with powerful individual punches in a contest where the approaches didn't complement each other, with excessive holding spoiling the action.
The scoring judges scored it 96-94 for to Buatsi, with the third a 95-95 draw.
"It wasn't my greatest showing but what do champions do? They prevail," Buatsi said in the ring as he was greeted with boos from the audience.
The British fighter returned to winning ways after his first professional defeat - an epic battle with his previous opponent in February - to earn a twentieth professional win.
Some ringside observers felt the challenger, 31, should have been awarded the victory but the contender endured the second setback of his 28-fight career.
Buatsi Claims Win in Uneventful Encounter
His career development has slowed in recent times through promotional disputes and considerable time of inactivity.
Previously predicted as the next star of UK boxing, he now stands trying to achieve expectations - possibly in what appears to be a last chance - under new promotional backing.
He opened tentatively, with neither fighter willing to overcommit in a calculated early stages.
Parker, whose sole prior loss came at super-middleweight against John Ryder in two years ago after breaking his hand during the bout, was making just his second fight at light-heavyweight.
By the halfway stage, Parker had stayed in contention, causing problems for Buatsi, who operated with a solid defense to edge the more effective periods.
The spectators' acceptance wore thin amid regular grabbing, with Parker going down several times during grappling.
The underdog ended stronger, but many rounds were difficult to score. However, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just one round.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Eastern European fighter Bivol ruling the division, the road to world glory - based on this performance - still appears challenging.
Hatton Homage Inspires All-Manchester Fight
In the co-main event, Arthur overcame Rea by divided decision in a outstanding all-Manchester fight to win the European light heavyweight championship.
The venue fell silent for a profoundly moving tribute before the fight as ten bells sounded in honor of Manchester's own Hatton, who passed away aged 46 in last month.
It was the initial significant broadcast fight night in the location since Hatton's passing. As the final chime disappeared, the silence became a roar of "there's only one Ricky Hatton".
The competition inside the ropes reflected the feeling. The eventual winner was floored by a significant blow squarely on the jaw in the initial stage, rising shakily to his position on the eight count.
But the red-colored equipment of the fighter soon came forward again. From the other corner, Rea - in opposing blue - was damaged quickly, significant bruising appearing under his eye as the pair exchanged powerful shots.
Rea, 27, delivered effective strikes but the champion, thirty-four, matched the intensity with stinging uppercuts as the pace seldom decreased over 12 rounds.
The victor barely secured the decision with scoring tallies of even score, narrow lead and clearer margin, but the two athletes were persistent and courageous, everything their idol Hatton represented.
