British light-heavyweight Joshua Buatsi made a winning yet disappointing start to life under fresh promotional backing with a points victory over Parker in Manchester.
The Olympic medal winner's work rate appeared to earn him a split decision in a close ten-round bout at the Manchester venue.
But Parker had his moments, connecting with powerful clean blows in a contest where the styles failed to mesh, with constant grabbing disrupting the contest.
The scoring judges had it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest display but how do champions respond? They succeed," the victor stated in the ringside as he was met by negative reactions from the spectators.
The Londoner returned to winning ways after his maiden career setback - an thrilling contest with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers believed the challenger, thirty-one, merited the win but the contender suffered the second defeat of his 28-fight career.
Buatsi Earns Win in Dull Match
Buatsi's progress has slowed in the past few years through promotional disputes and long spells of inactivity.
Once tipped as the rising talent of British boxing, he now finds himself trying to realize his potential - perhaps in what appears to be a last chance - under fresh management.
He began cautiously, with neither fighter willing to be aggressive in a cagey opening few rounds.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was participating in his second fight at light heavyweight.
By the halfway stage, Parker had made it competitive, making life awkward for Buatsi, who utilized a tight guard to barely take the better periods.
The audience's tolerance decreased during regular grabbing, with Parker falling to the floor several times during clinches.
Parker ended stronger, but several stanzas were difficult to score. However, ex-champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, giving Buatsi just one round.
Buatsi moves on, but with the caliber of heavy hitter Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - on this evidence - still seems difficult.
Ricky Hatton Homage Motivates Local Rivalry Contest
In the secondary fight, Arthur overcame Rea by divided decision in a excellent all-Manchester fight to capture the European light heavyweight championship.
The stadium fell silent for a deeply poignant homage ahead of the contest as a bell ceremony rang in remembrance of the city's native Ricky Hatton, who succumbed 46 years old in September.
It was the initial significant broadcast boxing event in the city since Hatton's passing. As the final chime disappeared, the stillness gave way to a chant of "only one Hatton".
The fighting within the ring equaled the emotion. The eventual winner was sent to the canvas by a significant blow squarely on the chin in the initial stage, rising shakily to his footing on the count of eight.
But the Manchester United-red equipment of the fighter soon pressed ahead again. From the other corner, Rea - in competitive blue - was marked up soon, significant bruising forming under his eye as the pair exchanged hard punches.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with stinging uppercuts as the action seldom decreased over 12 rounds.
The victor edged the result with official scores of 114-114, close margin and wider gap, but both fighters were determined and courageous, all the qualities their idol Hatton embodied.
