British light-heavyweight Joshua Buatsi made a winning yet unimpressive start to life under new promoters with a points victory over Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a competitive 10-round contest at the boxing arena.
But the challenger had his moments, landing some telling single shots in a contest where the techniques failed to mesh, with constant grabbing marring the action.
The scoring judges had it 96-94 to the winner, with the final judge a even score.
"It wasn't my best performance but how do champions respond? They prevail," Buatsi said in the ringside as he was greeted with disapproval from the crowd.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers believed the challenger, 31, should have been awarded the win but the contender endured the second loss of his 28-bout professional journey.
Buatsi Claims Win in Dull Match
The fighter's advancement has stalled in the past few years through promotional disputes and long spells of inactivity.
Earlier forecast as the next star of UK boxing, he now is positioned trying to realize his potential - perhaps in what appears to be a last chance - under recent support.
He began cautiously, with neither fighter prepared to overcommit in a tentative opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in two years ago after damaging his hand during the bout, was competing in only his second bout at light heavyweight.
By the fight's midpoint, Parker had kept it close, creating difficulties for Buatsi, who operated with a protective stance to edge the better stanzas.
The crowd's patience diminished because of regular grabbing, with the challenger going down several times during clinches.
The underdog finished the stronger, but many rounds were hard to judge. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for the challenger, giving Buatsi just one round.
The victor advances, but with the presence of hard hitter Benavidez, and Russian champion Bivol dominating the weight class, the path to championship success - on this evidence - still seems difficult.
Hatton Homage Inspires Manchester Derby Contest
In the supporting bout, Arthur defeated Rea by split-decision in a outstanding local rivalry fight to win the continental championship.
The stadium fell silent for a deeply poignant tribute prior to the bout as a bell ceremony sounded in honor of Manchester's own Ricky Hatton, who succumbed at age 46 in last month.
It was the initial significant broadcast fight night in the urban center since the passing of Hatton. As the final chime faded, the quiet gave way to a chant of "only one Hatton".
The competition during the bout equaled the emotion. Arthur was floored by a left hook squarely on the face in the early round, rising shakily to his footing on the referee's count.
But the traditional red shorts of the fighter soon advanced again. From the other corner, the opponent - in opposing blue - was marked up early, significant bruising forming under his eye as the pair landed powerful shots.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with effective uppercuts as the pace rarely dropped over the full distance.
The victor edged the decision with judges scorecards of 114-114, 115-113 and 115-112, but the two athletes were determined and full of heart, exactly what their inspiration the legend stood for.
