British light heavyweight Joshua Buatsi secured a victory yet unimpressive debut to life under new promoters with a points victory over Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a majority decision in a competitive ten-round bout at the boxing arena.
But the challenger landed significant shots, connecting with powerful clean blows in a fight where the approaches failed to mesh, with frequent clinching disrupting the fight.
The officials judged it 96-94 for to Buatsi, with the third a even score.
"It wasn't my best performance but what do champions do? They win," Buatsi stated in the arena as he was faced disapproval from the spectators.
The British fighter bounced back after his first professional defeat - an memorable fight with his previous opponent in February - to claim a 20th pro success.
Various analysts thought the challenger, thirty-one, should have been awarded the win but the contender endured the second loss of his 28-fight professional journey.
The Champion Earns Triumph in Dull Match
Buatsi's progress has slowed in the past few years through management issues and long spells of lack of fights.
Previously predicted as the rising talent of UK boxing, he now stands trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under recent support.
He started carefully, with neither fighter prepared to take risks in a cagey initial rounds.
The challenger, whose sole prior loss came at super-middleweight against John Ryder in two years ago after breaking his hand during the bout, was competing in only his second bout at light heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who utilized a protective stance to edge the better rounds.
The audience's tolerance decreased amid frequent holding, with Parker falling to the floor multiple occasions during close exchanges.
Parker closed well, but many rounds were difficult to score. However, former world champion the boxing analyst - commentating on Dazn - had it particularly wide for Parker, giving Buatsi just only one stanza.
Buatsi advances, but with the likes of heavy hitter Benavidez, and Russian champion Bivol ruling the division, the road to world glory - judging by this showing - still appears challenging.
Hatton Memorial Inspires Manchester Derby Fight
In the secondary fight, Arthur beat Rea by split-decision in a excellent local rivalry fight to secure the continental championship.
The arena grew hushed for a profoundly moving memorial before the fight as a bell ceremony rang in memory of the city's native Ricky Hatton, who passed away 46 years old in September.
It was the initial significant broadcast match card in the location since Hatton's death. As the final chime disappeared, the stillness gave way to a roar of "there's only one Hatton".
The fighting within the ring reflected the emotion. The eventual winner was floored by a powerful punch flush on the jaw in the initial stage, getting up unsteadily to his position on the eight count.
But the red-colored attire of Arthur soon advanced again. Across the ring, Rea - in opposing blue - was injured soon, noticeable damage developing under his eye as the pair landed hard punches.
Rea, 27, connected with strong blows but the champion, thirty-four, responded in kind with effective uppercuts as the pace rarely dropped over twelve rounds.
Arthur narrowly won the verdict with official scores of even score, narrow lead and wider gap, but the two athletes were persistent and full of heart, exactly what their inspiration the legend stood for.
