UK light heavyweight Buatsi made a winning yet disappointing beginning to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a tight ten-round contest at the Manchester venue.
But Parker found success, connecting with powerful clean blows in a contest where the techniques didn't complement each other, with frequent clinching spoiling the fight.
The scoring judges judged it 96-94 in favor to Buatsi, with the final judge a even score.
"It wasn't my finest showing but what defines champions? They succeed," the victor said in the arena as he was met by negative reactions from the spectators.
The British fighter returned to winning ways after his maiden career setback - an memorable fight with Callum Smith in February - to earn a 20th career victory.
Several boxing experts believed Parker, thirty-one, merited the victory but the Derbyshire fighter endured the second defeat of his 28-match career.
Buatsi Earns Victory in Slow Match
The fighter's advancement has plateaued in the past few years through contract problems and extended periods of lack of fights.
Once tipped as the next star of British boxing, he now stands trying to achieve expectations - possibly in what appears to be a last chance - under recent support.
He began cautiously, with neither fighter willing to overcommit in a cagey initial rounds.
Parker, whose only previous defeat came at super middleweight against his former opponent in two years ago after suffering a hand injury mid-fight, was making just his second appearance at light heavyweight.
By the halfway stage, Parker had kept it close, causing problems for the favorite, who utilized a tight guard to narrowly win the better periods.
The spectators' acceptance wore thin amid regular grabbing, with the challenger slipping to the canvas various instances during grappling.
Parker closed well, but several stanzas were difficult to score. Nevertheless, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of hard hitter David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still seems difficult.
Hatton Homage Inspires Local Rivalry Contest
In the co-main event, Arthur beat Bradley Rea by split-decision in a excellent Manchester vs Manchester fight to win the European light-heavyweight belt.
The stadium fell silent for a extremely emotional tribute ahead of the contest as a bell ceremony tolled in memory of local hero Ricky Hatton, who passed away at age 46 in September.
It was the premier televised match card in the urban center since Hatton's death. As the final chime faded, the silence gave way to a shout of "there's only one Hatton".
The action within the ring matched the sentiment. Arthur was sent to the canvas by a left hook flush on the face in the initial stage, rising shakily to his position on the referee's count.
But the red-colored equipment of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was injured quickly, noticeable damage forming under his face as the fighters exchanged powerful shots.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with effective uppercuts as the action seldom decreased over 12 rounds.
The victor narrowly won the verdict with judges scorecards of even score, 115-113 and clearer margin, but each competitor were persistent and courageous, everything their hero Hatton represented.
