UK light heavyweight Joshua Buatsi earned a win yet disappointing beginning to his career under new promoters with a decision win over Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a competitive ten-round fight at the Manchester venue.
But Parker found success, landing some telling individual punches in a match where the styles never quite clicked, with excessive holding marring the fight.
The officials had it 96-94 to the winner, with the remaining official a 95-95 draw.
"It wasn't my best display but what defines champions? They prevail," Buatsi stated in the ringside as he was faced disapproval from the audience.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in last winter - to claim a twentieth professional win.
Some ringside observers thought the challenger, 31, should have been awarded the decision but the Derbyshire fighter experienced the second loss of his 28-fight career.
Buatsi Earns Victory in Slow Affair
His career development has plateaued in recent years through promotional disputes and extended periods of lack of fights.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to achieve expectations - maybe in what appears to be a last chance - under new promotional backing.
He started carefully, with the two boxers prepared to be aggressive in a cagey opening few rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder 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 stayed in contention, creating difficulties for Buatsi, who worked behind a protective stance to narrowly win the cleaner rounds.
The audience's tolerance diminished because of constant clinching, with the challenger falling to the floor multiple occasions during close exchanges.
Parker finished the stronger, but multiple periods were difficult to score. Although, ex-champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just one round.
The victor moves on, but with the likes of hard hitter Benavidez, and Russian champion Bivol dominating the weight class, the journey to titles - judging by this showing - still looks steep.
Hatton Homage Motivates Local Rivalry Battle
In the supporting bout, Arthur defeated Bradley Rea by divided decision in a terrific Manchester vs Manchester contest to secure the continental belt.
The arena became quiet for a profoundly moving memorial prior to the bout as a bell ceremony tolled in honor of local hero Hatton, who succumbed 46 years old in last month.
It was the initial significant broadcast fight night in the urban center since the passing of Hatton. As the final chime ended, the silence transitioned to a roar of "there's just one Ricky Hatton".
The competition inside the ropes reflected the sentiment. Arthur was sent to the canvas by a left hook flush on the face in the initial stage, rising shakily to his position on the eight count.
But the traditional red shorts of Arthur soon came forward again. From the other corner, the opponent - in competitive blue - was injured soon, noticeable damage forming under his eye as the pair landed hard punches.
Rea, 27, delivered effective strikes but the champion, thirty-four, responded in kind with stinging uppercuts as the intensity seldom decreased over the full distance.
The victor narrowly won the verdict with scoring tallies of even score, close margin and 115-112, but the two athletes were determined and courageous, all the qualities their hero Hatton embodied.
