British light-heavyweight Joshua Buatsi secured a victory yet unimpressive beginning to his career under new promoters with a unanimous decision over Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a competitive 10-round bout at the Co-op Live Arena.
But the challenger had his moments, delivering effective clean blows in a fight where the techniques never quite clicked, with excessive holding spoiling the fight.
Two judges judged it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my finest display but what defines champions? They prevail," the victor commented in the ringside as he was met by negative reactions from the audience.
The Londoner got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to secure a 20th career victory.
Various analysts believed the challenger, thirty-one, merited the victory but the Derbyshire fighter endured the second loss of his 28-match professional journey.
The Champion Claims Victory in Dull Encounter
The fighter's advancement has slowed in recent times through management issues and long spells of inactivity.
Previously predicted as the rising talent of the British fight scene, he now finds himself trying to achieve expectations - maybe in what appears to be a last chance - under recent support.
He started carefully, with neither fighter prepared to overcommit in a tentative opening few rounds.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago 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, making life awkward for the favorite, who utilized a solid defense to edge the more effective stanzas.
The audience's tolerance diminished amid frequent holding, with Parker going down several times during clinches.
The underdog closed well, but multiple periods were challenging to assess. However, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of power puncher Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - judging by this showing - still appears challenging.
Hatton Memorial Motivates Local Rivalry Fight
In the supporting bout, Arthur overcame Bradley Rea by divided decision in a excellent Manchester vs Manchester contest to capture the continental title.
The arena grew hushed for a deeply poignant memorial before the fight as 10 bells tolled in honor of local hero Hatton, who succumbed at age 46 in September.
It was the premier televised fight night in the city since Hatton's passing. As the final chime faded, the silence gave way to a roar of "there's just one Hatton".
The action within the ring matched the sentiment. The eventual winner was floored by a left hook squarely on the chin in the early round, standing uncertainly to his position on the count of eight.
But the red-colored equipment of Arthur soon advanced again. Across the ring, the opponent - in competitive blue - was injured soon, noticeable damage forming under his eye as the duo exchanged powerful shots.
Rea, 27, delivered effective strikes but the champion, 34, fought fire with fire with effective uppercuts as the pace rarely dropped over 12 rounds.
The victor edged the decision with official scores of 114-114, 115-113 and wider gap, but the two athletes were relentless and brave, exactly what their idol Hatton stood for.
