British light heavyweight Joshua Buatsi earned a win yet unimpressive debut to his career under fresh promotional backing with a decision win over Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a judges' verdict in a competitive ten-round contest at the boxing arena.
But Parker found success, landing some telling clean blows in a match where the styles never quite clicked, with excessive holding disrupting the action.
The officials judged it 96-94 for to the winner, with the remaining official a even score.
"It wasn't my finest display but how do champions respond? They win," Buatsi stated in the ring as he was faced negative reactions from the crowd.
The British fighter bounced back after his first professional defeat - an memorable fight with Callum Smith in February - to secure a 20th pro success.
Some ringside observers thought Parker, thirty-one, should have been awarded the victory but the Derbyshire fighter endured the second loss of his 28-fight professional journey.
Buatsi Secures Victory in Dull Encounter
The fighter's advancement has slowed in recent years through promotional disputes and extended periods of inactivity.
Previously predicted as the future of the British fight scene, he now finds himself trying to realize his potential - perhaps in what feels like a last chance - under fresh management.
He began cautiously, with the two boxers ready to overcommit in a tentative opening few rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after breaking his hand during the bout, was making just his second appearance at light heavyweight.
By the middle rounds, Parker had kept it close, creating difficulties for the favorite, who utilized a protective stance to barely take the better periods.
The audience's tolerance wore thin during regular grabbing, with the challenger falling to the floor various instances during clinches.
Parker ended stronger, but multiple periods were challenging to assess. Although, ex-champion the boxing analyst - commentating on Dazn - had it particularly wide for Parker, giving Buatsi just only one stanza.
Buatsi advances, but with the caliber of power puncher David Benavidez, and Russian champion Dmitry Bivol leading the category, the path to championship success - on this evidence - still seems difficult.
Hatton Memorial Motivates Local Rivalry Battle
In the co-main event, Lyndon Arthur beat Rea by close verdict in a excellent local rivalry battle to capture the European light-heavyweight championship.
The venue fell silent for a extremely emotional memorial ahead of the contest as ten bells tolled in memory of the city's native Ricky Hatton, who passed away 46 years old in last month.
It was the premier televised match card in the urban center since the passing of Hatton. As the concluding sound faded, the silence became a roar of "only one Ricky Hatton".
The fighting within the ring equaled the feeling. The eventual winner was sent to the canvas by a significant blow flush on the chin in the second round, rising shakily to his footing on the eight count.
But the red-colored equipment of the fighter soon advanced again. From the other corner, the opponent - in rival City blue - was damaged quickly, significant bruising developing under his face as the duo landed punishing blows.
Rea, 27, connected with strong blows but Arthur, 34, matched the intensity with powerful upward punches as the action rarely dropped over the full distance.
The victor barely secured the result with scoring tallies of draw, close margin and 115-112, but both fighters were persistent and courageous, exactly what their idol Hatton represented.
