British light heavyweight Joshua Buatsi made a winning yet unimpressive beginning to life under new promoters with a points victory over Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a close ten-round bout at the Co-op Live Arena.
But the challenger had his moments, connecting with powerful single shots in a match where the techniques didn't complement each other, with constant grabbing marring the action.
The officials judged it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my best performance but what do champions do? They succeed," Buatsi said in the ringside as he was greeted with negative reactions from the spectators.
The Londoner got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Various analysts felt the challenger, 31, merited the decision but the Derbyshire fighter endured the second loss of his 28-bout career.
Buatsi Earns Victory in Dull Affair
The fighter's advancement has slowed in recent times through management issues and extended periods of inactivity.
Earlier forecast as the next star of UK boxing, he now stands trying to realize his potential - possibly in what appears to be a last chance - under fresh management.
He opened tentatively, with both competitors ready to overcommit in a calculated opening few rounds.
The challenger, whose single earlier setback came at super middleweight against John Ryder in 2022 after damaging his hand mid-fight, was participating in his second bout at light-heavyweight.
By the fight's midpoint, Parker had made it competitive, making life awkward for the favorite, who utilized a solid defense to edge the more effective periods.
The audience's tolerance wore thin because of regular grabbing, with Parker slipping to the canvas multiple occasions during clinches.
The underdog finished the stronger, but several stanzas were difficult to score. Nevertheless, former world champion the boxing analyst - working with Dazn - had it significantly in favor for Parker, awarding Buatsi just only one stanza.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Homage Inspires Local Rivalry Contest
In the co-main event, Arthur beat Bradley Rea by divided decision in a excellent local rivalry contest to win the European light-heavyweight belt.
The venue grew hushed for a deeply poignant memorial before the fight as ten bells rang in memory of the city's native Ricky Hatton, who died aged 46 in recently.
It was the initial significant broadcast boxing event in the location since Hatton's passing. As the final chime disappeared, the silence became a roar of "there's just one Hatton".
The action inside the ropes reflected the sentiment. Arthur was knocked down by a left hook directly to the chin in the second round, getting up unsteadily to his footing on the count of eight.
But the red-colored shorts of Arthur soon advanced again. From the other corner, the opponent - in rival City blue - was damaged soon, noticeable damage developing under his face as the pair landed powerful shots.
Rea, 27, connected with strong blows but Arthur, thirty-four, fought fire with fire with effective uppercuts as the action rarely dropped over 12 rounds.
Arthur edged the verdict with scoring tallies of draw, close margin and 115-112, but the two athletes were relentless and full of heart, exactly what their hero the legend represented.
