British light heavyweight Joshua Buatsi secured a victory yet disappointing beginning to his career under fresh promotional backing with a points victory over Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a split decision in a competitive 10-round fight at the Co-op Live Arena.
But Parker found success, landing some telling clean blows in a match where the techniques failed to mesh, with excessive holding disrupting the contest.
The officials judged it 96-94 for to Buatsi, with the remaining official a 95-95.
"It wasn't my greatest showing but how do champions respond? They win," the victor commented in the arena as he was faced negative reactions from the crowd.
The British fighter returned to winning ways after his initial pro loss - an memorable fight with Callum Smith in last winter - to secure a 20th career victory.
Some ringside observers thought the challenger, thirty-one, should have been awarded the win but the Derbyshire fighter experienced the second defeat of his 28-bout career.
The Champion Claims Win in Slow Encounter
The fighter's advancement has plateaued in the past few years through promotional disputes and considerable time of inactivity.
Earlier forecast as the future of British boxing, he now finds himself trying to realize his potential - perhaps in what appears to be a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter ready to take risks in a cagey opening few rounds.
Parker, whose sole prior loss came at super middleweight against his former opponent in two years ago after damaging his hand mid-fight, was making just his second bout at light-heavyweight.
By the middle rounds, Parker had stayed in contention, making life awkward for the favorite, who utilized a tight guard to barely take the more effective periods.
The audience's tolerance diminished during regular grabbing, with the challenger falling to the floor various instances during close exchanges.
The underdog finished the stronger, but multiple periods were challenging to assess. However, ex-champion Carl Frampton - providing analysis for the broadcast network - had it significantly in favor for the challenger, scoring for Buatsi just a single round.
The victor advances, but with the likes of heavy hitter Benavidez, and Eastern European fighter Bivol dominating the weight class, the path to championship success - judging by this showing - still appears challenging.
Ricky Hatton Homage Fuels Local Rivalry Battle
In the secondary fight, Lyndon Arthur defeated Bradley Rea by divided decision in a excellent local rivalry contest to capture the European light heavyweight title.
The arena fell silent for a extremely emotional homage prior to the bout as a bell ceremony tolled in remembrance of the city's native Hatton, who succumbed 46 years old in September.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the concluding sound ended, the stillness transitioned to a shout of "there's only one Ricky Hatton".
The action within the ring equaled the emotion. The eventual winner was floored by a left hook flush on the face in the initial stage, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of the fighter soon advanced again. On the opposite side, the opponent - in competitive blue - was marked up quickly, noticeable damage appearing under his face as the fighters traded punishing blows.
Rea, 27, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the pace rarely dropped over twelve rounds.
Arthur barely secured the result with scoring tallies of 114-114, 115-113 and clearer margin, but the two athletes were determined and brave, all the qualities their inspiration Hatton stood for.
