UK light heavyweight Joshua Buatsi made a winning yet underwhelming debut to his career under new promoters with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a competitive ten-round bout at the Manchester venue.
But the challenger had his moments, connecting with powerful individual punches in a match where the approaches never quite clicked, with constant grabbing disrupting the fight.
The officials judged it 96-94 in favor to Buatsi, with the final judge a 95-95.
"It wasn't my greatest performance but what do champions do? They win," Buatsi commented in the arena as he was faced negative reactions from the spectators.
The British fighter bounced back after his first professional defeat - an thrilling contest with his previous opponent in February - to earn a 20th career victory.
Several boxing experts felt the challenger, 31, merited the decision but the British boxer experienced the second setback of his 28-bout professional journey.
Buatsi Earns Win in Slow Affair
The fighter's advancement has slowed in the past few years through management issues and considerable time of inactivity.
Earlier forecast as the future of the British fight scene, he now finds himself trying to realize his potential - maybe in what seems like a last chance - under recent support.
He began cautiously, with the two boxers willing to overcommit in a cagey opening few rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was participating in his second bout at light-heavyweight.
By the halfway stage, Parker had made it competitive, causing problems for Buatsi, who utilized a tight guard to narrowly win the cleaner rounds.
The audience's tolerance diminished during frequent holding, with the challenger slipping to the canvas various instances during close exchanges.
Parker closed well, but many rounds were difficult to score. However, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, awarding Buatsi just only one stanza.
The victor progresses, but with the likes of hard hitter Benavidez, and Russian star Dmitry Bivol dominating the weight class, the journey to titles - on this evidence - still seems difficult.
Ricky Hatton Memorial Inspires All-Manchester Battle
In the co-main event, Lyndon Arthur overcame Rea by close verdict in a outstanding Manchester vs Manchester contest to win the European light-heavyweight championship.
The venue grew hushed for a deeply poignant homage before the fight as a bell ceremony sounded in remembrance of the city's native Hatton, who passed away 46 years old in September.
It was the initial significant broadcast fight night in the city since the passing of Hatton. As the final chime ended, the quiet gave way to a chant of "there's only one Ricky Hatton".
The fighting within the ring matched the emotion. The eventual winner was knocked down by a significant blow directly to the jaw in the initial stage, getting up unsteadily to his feet on the eight count.
But the red-colored attire of Arthur soon pressed ahead again. From the other corner, Rea - in opposing blue - was injured soon, noticeable damage developing under his orbital area as the duo landed hard punches.
Rea, twenty-seven, delivered effective strikes but the champion, 34, matched the intensity with stinging uppercuts as the action hardly diminished over twelve rounds.
Arthur narrowly won the verdict with judges scorecards of even score, narrow lead and 115-112, but the two athletes were determined and courageous, exactly what their idol the legend stood for.
