UK light heavyweight Joshua Buatsi made a winning yet disappointing debut to life under new promoters with a unanimous decision over Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a close ten-round contest at the Manchester venue.
But the challenger had his moments, connecting with powerful clean blows in a match where the approaches didn't complement each other, with frequent clinching disrupting the contest.
Two judges had it 96-94 for to Buatsi, with the third a 95-95.
"It wasn't my finest showing but what defines champions? They succeed," Buatsi stated in the ringside as he was faced disapproval from the audience.
The Londoner returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in February - to earn a 20th career victory.
Various analysts felt the challenger, thirty-one, should have been awarded the victory but the British boxer suffered the second setback of his 28-match professional journey.
Buatsi Earns Win in Uneventful Match
Buatsi's progress has stalled in recent times through promotional disputes and considerable time of lack of fights.
Once tipped as the future of UK boxing, he now finds himself trying to achieve expectations - maybe in what appears to be a final roll of the dice - under new promotional backing.
He started carefully, with neither fighter willing to be aggressive in a tentative initial rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after breaking his hand mid-fight, was making just his second appearance at light heavyweight.
By the halfway stage, Parker had stayed in contention, creating difficulties for Buatsi, who utilized a solid defense to narrowly win the cleaner rounds.
The spectators' acceptance wore thin amid regular grabbing, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog closed well, but several stanzas were challenging to assess. However, former world champion the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, awarding Buatsi just only one stanza.
Buatsi moves on, but with the presence of hard hitter David Benavidez, and Russian champion Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Homage Inspires Local Rivalry Battle
In the secondary fight, Lyndon Arthur defeated Bradley Rea by close verdict in a excellent local rivalry battle to win the European light-heavyweight championship.
The arena became quiet for a extremely emotional memorial prior to the bout as ten bells tolled in honor of local hero Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast match card in the city since the passing of Hatton. As the concluding sound ended, the silence gave way to a shout of "only one Ricky Hatton".
The competition within the ring reflected the sentiment. The eventual winner was knocked down by a powerful punch squarely on the face in the second round, rising shakily to his feet on the referee's count.
But the Manchester United-red attire of Arthur soon came forward again. From the other corner, Rea - in rival City blue - was damaged soon, heavy swelling developing under his eye as the duo traded hard punches.
Rea, twenty-seven, delivered effective strikes but the champion, thirty-four, fought fire with fire with effective uppercuts as the intensity seldom decreased over twelve rounds.
Arthur narrowly won the decision with official scores of even score, close margin and clearer margin, but both fighters were relentless and full of heart, exactly what their hero the legend embodied.
