UK light-heavyweight Joshua Buatsi secured a victory yet unimpressive beginning to life under new promoters with a unanimous decision over Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a majority decision in a close ten-round fight at the Manchester venue.
But Parker landed significant shots, landing some telling individual punches in a contest where the approaches failed to mesh, with excessive holding marring the fight.
The scoring judges had it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my greatest display but what defines champions? They win," Buatsi stated in the ring as he was greeted with disapproval from the spectators.
The British fighter got back to winning after his first professional defeat - an epic battle with his previous opponent in last winter - to earn a 20th career victory.
Several boxing experts felt the challenger, thirty-one, should have been awarded the victory but the contender suffered the second loss of his 28-match professional journey.
Buatsi Claims Triumph in Dull Encounter
Buatsi's progress has stalled in the past few years through promotional disputes and extended periods of inactivity.
Once tipped as the next star of UK boxing, he now is positioned trying to achieve expectations - maybe in what feels like a ultimate opportunity - under recent support.
He started carefully, with the two boxers prepared to take risks in a tentative initial rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after damaging his hand in the contest, was participating in his second bout at light heavyweight.
By the middle rounds, the underdog had kept it close, causing problems for Buatsi, who utilized a tight guard to barely take the more effective rounds.
The audience's tolerance wore thin because of constant clinching, with Parker falling to the floor various instances during close exchanges.
The underdog closed well, but several stanzas were hard to judge. However, former world champion Carl Frampton - working with Dazn - had it strongly leaning for the challenger, awarding Buatsi just one round.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Eastern European fighter Bivol dominating the weight class, the path to championship success - based on this performance - still seems difficult.
Hatton Homage Fuels Local Rivalry Fight
In the co-main event, Arthur overcame Bradley Rea by divided decision in a excellent Manchester vs Manchester battle to capture the continental title.
The stadium became quiet for a extremely emotional tribute prior to the bout as ten bells rang in remembrance of local hero Ricky Hatton, who passed away aged 46 in last month.
It was the initial significant broadcast fight night in the urban center since Hatton's passing. As the last bell ended, the stillness gave way to a shout of "only one Ricky Hatton".
The fighting within the ring reflected the emotion. Arthur was knocked down by a significant blow flush on the jaw in the second round, rising shakily to his footing on the eight count.
But the red-colored equipment of the fighter soon pressed ahead again. From the other corner, the opponent - in competitive blue - was injured quickly, noticeable damage appearing under his face as the pair landed powerful shots.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with powerful upward punches as the intensity seldom decreased over 12 rounds.
The victor edged the result with judges scorecards of 114-114, close margin and 115-112, but both fighters were persistent and brave, everything their idol Hatton represented.
