British light heavyweight Buatsi made a winning yet underwhelming beginning to life under recent management with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a close ten-round contest at the Manchester venue.
But Parker landed significant shots, connecting with powerful clean blows in a contest where the techniques didn't complement each other, with constant grabbing spoiling the action.
The officials judged it 96-94 in favor to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest display but how do champions respond? They succeed," Buatsi commented in the arena as he was met by boos from the audience.
The British fighter bounced back after his maiden career setback - an memorable fight with his previous opponent in February - to claim a 20th career victory.
Several boxing experts thought Parker, thirty-one, should have been awarded the victory but the Derbyshire fighter suffered the second defeat of his 28-bout professional journey.
The Champion Earns Victory in Slow Match
Buatsi's progress has plateaued in recent years through management issues and extended periods of inactivity.
Earlier forecast as the next star of the British fight scene, he now is positioned trying to fulfil that early promise - maybe in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors ready to be aggressive in a tentative initial rounds.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in two years ago after suffering a hand injury during the bout, was competing in only his second fight at the higher weight class.
By the fight's midpoint, Parker had made it competitive, causing problems for Buatsi, who worked behind a protective stance to barely take the more effective periods.
The audience's tolerance wore thin during constant clinching, with Parker going down multiple occasions during clinches.
The underdog finished the stronger, but many rounds were difficult to score. Although, former world champion the boxing analyst - commentating on the broadcast network - had it particularly wide for Parker, awarding Buatsi just only one stanza.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still appears challenging.
Hatton Homage Fuels Local Rivalry Contest
In the co-main event, Arthur beat Rea by close verdict in a terrific local rivalry fight to capture the continental championship.
The venue became quiet for a extremely emotional tribute ahead of the contest as 10 bells rang in remembrance of Manchester's own Hatton, who died aged 46 in last month.
It was the first major televised fight night in the location since Hatton's passing. As the concluding sound ended, the quiet became a chant of "only one Hatton".
The competition inside the ropes reflected the feeling. Arthur was knocked down by a powerful punch directly to the jaw in the second round, getting up unsteadily to his footing on the count of eight.
But the traditional red equipment of the fighter soon came forward again. Across the ring, the opponent - in opposing blue - was damaged early, significant bruising appearing under his orbital area as the duo landed powerful shots.
The challenger, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the action seldom decreased over 12 rounds.
The victor narrowly won the verdict with scoring tallies of draw, close margin and wider gap, but each competitor were persistent and full of heart, all the qualities their hero the legend represented.
