UK light heavyweight Joshua Buatsi secured a victory yet unimpressive start to his career under fresh promotional backing with a unanimous decision over Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a competitive ten-round bout at the boxing arena.
But Parker landed significant shots, connecting with powerful single shots in a fight where the styles didn't complement each other, with constant grabbing disrupting the contest.
The scoring judges scored it 96-94 to the winner, with the final judge a even score.
"It wasn't my finest showing but what do champions do? They succeed," Buatsi said in the arena as he was met by negative reactions from the spectators.
The British fighter bounced back after his initial pro loss - an memorable fight with Callum Smith in February - to earn a 20th pro success.
Some ringside observers believed the challenger, 31, should have been awarded the victory but the Derbyshire fighter suffered the second setback of his 28-match professional journey.
The fighter's advancement has stalled in the past few years through promotional disputes and extended periods of lack of fights.
Previously predicted as the future of UK boxing, 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 opened tentatively, with neither fighter willing to overcommit in a tentative initial rounds.
The challenger, whose sole prior loss came at super-middleweight against his former opponent in two years ago after damaging his hand mid-fight, was making just his second fight at light heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for the favorite, who operated with a protective stance to edge the cleaner rounds.
The spectators' acceptance decreased because of regular grabbing, with the challenger slipping to the canvas multiple occasions during clinches.
Parker closed well, but many rounds were challenging to assess. However, ex-champion Carl Frampton - working with Dazn - had it particularly wide for the challenger, awarding Buatsi just a single round.
Buatsi advances, but with the presence of power puncher Benavidez, and Russian star Bivol leading the category, the road to world glory - based on this performance - still looks steep.
In the supporting bout, Arthur beat Rea by split-decision in a terrific all-Manchester fight to win the European light heavyweight belt.
The venue fell silent for a profoundly moving tribute before the fight as 10 bells sounded in honor of the city's native Hatton, who died 46 years old in last month.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the concluding sound faded, the silence transitioned to a chant of "there's only one Ricky Hatton".
The competition during the bout reflected the emotion. Arthur was knocked down by a significant blow directly to the chin in the early round, standing uncertainly to his footing on the eight count.
But the red-colored shorts of Arthur soon came forward again. Across the ring, the opponent - in competitive blue - was damaged quickly, noticeable damage developing under his face as the fighters traded punishing blows.
Rea, twenty-seven, connected with strong blows but Arthur, 34, fought fire with fire with powerful upward punches as the pace hardly diminished over twelve rounds.
Arthur edged the verdict with judges scorecards of 114-114, 115-113 and wider gap, but each competitor were determined and brave, everything their inspiration the legend represented.
Lena Visser is a mindfulness coach and writer passionate about helping others find inner peace.