British light-heavyweight Joshua Buatsi made a winning yet unimpressive beginning to his career under recent management with a decision win over Parker in the Manchester arena.
The Olympic medal winner's punch output seemingly secured him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful clean blows in a fight where the styles failed to mesh, with constant grabbing spoiling the action.
Two judges scored it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my finest display but what defines champions? They prevail," the victor commented in the arena as he was met by negative reactions from the spectators.
The Londoner got back to winning after his initial pro loss - an memorable fight with his previous opponent in last winter - to claim a 20th career victory.
Several boxing experts thought the challenger, thirty-one, should have been awarded the victory but the British boxer endured the second setback of his 28-fight professional journey.
The Champion Earns Win in Uneventful Affair
The fighter's advancement has plateaued in recent times through management issues and long spells of inactivity.
Earlier forecast as the future of the British fight scene, he now stands trying to realize his potential - possibly in what seems like a last chance - under new promotional backing.
He started carefully, with neither fighter willing to take risks in a tentative early stages.
The challenger, whose single earlier setback came at super-middleweight against John Ryder in two years ago after breaking his hand mid-fight, was competing in only his second bout at light heavyweight.
By the fight's midpoint, Parker had stayed in contention, creating difficulties for Buatsi, who worked behind a solid defense to barely take the more effective stanzas.
The spectators' acceptance diminished during frequent holding, with the challenger going down various instances during close exchanges.
The underdog ended stronger, but many rounds were hard to judge. Nevertheless, previous titleholder the boxing analyst - working with Dazn - had it significantly in favor for the challenger, giving Buatsi just one round.
Buatsi advances, but with the likes of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Homage Fuels All-Manchester Fight
In the co-main event, Lyndon Arthur defeated Rea by close verdict in a excellent all-Manchester fight to win the continental championship.
The arena fell silent for a profoundly moving homage prior to the bout as 10 bells sounded in remembrance of the city's native Hatton, who passed away aged 46 in September.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the final chime disappeared, the quiet gave way to a chant of "there's only one Hatton".
The competition during the bout equaled the emotion. The eventual winner was floored by a powerful punch directly to the chin in the initial stage, standing uncertainly to his position on the count of eight.
But the red-colored attire of the fighter soon came forward again. On the opposite side, the opponent - in opposing blue - was damaged soon, heavy swelling forming under his face as the duo exchanged hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, matched the intensity with powerful upward punches as the pace hardly diminished over 12 rounds.
Arthur barely secured the verdict with judges scorecards of draw, close margin and wider gap, but each competitor were persistent and brave, exactly what their inspiration the legend represented.
