British light-heavyweight Joshua Buatsi earned a win yet disappointing start to his career under fresh promotional backing with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's activity level likely gained him a judges' verdict in a tight 10-round fight at the Co-op Live Arena.
But Parker had his moments, connecting with powerful clean blows in a contest where the styles never quite clicked, with excessive holding spoiling the contest.
Two judges scored it 96-94 for to the winner, with the third a 95-95.
"It wasn't my finest display but how do champions respond? They win," Buatsi stated in the arena as he was faced boos from the audience.
The British fighter got back to winning after his first professional defeat - an memorable fight with Callum Smith in last winter - to claim a twentieth professional win.
Several boxing experts felt the challenger, thirty-one, deserved the decision but the Derbyshire fighter experienced the second setback of his 28-match career.
The Champion Secures Win in Uneventful Encounter
His career development has stalled in recent years through contract problems and extended periods of inactivity.
Previously predicted as the next star of British boxing, he now finds himself trying to achieve expectations - maybe in what seems like a last chance - under recent support.
He opened tentatively, with both competitors willing to be aggressive in a cagey initial rounds.
Parker, whose single earlier setback came at super middleweight against his former opponent in two years ago after breaking his hand in the contest, was participating in his second bout at light heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who utilized a protective stance to barely take the cleaner stanzas.
The audience's tolerance diminished amid constant clinching, with the challenger falling to the floor various instances during grappling.
The underdog finished the stronger, but several stanzas were hard to judge. Nevertheless, former world champion Carl Frampton - working with Dazn - had it strongly leaning for the challenger, awarding Buatsi just a single round.
Buatsi progresses, but with the caliber of heavy hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Homage Fuels Local Rivalry Fight
In the secondary fight, Lyndon Arthur beat Bradley Rea by divided decision in a outstanding local rivalry battle to capture the European light heavyweight belt.
The arena fell silent for a profoundly moving tribute before the fight as a bell ceremony tolled in memory of local hero Hatton, who succumbed at age 46 in recently.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the last bell faded, the silence gave way to a shout of "there's just one Ricky Hatton".
The competition inside the ropes equaled the feeling. Arthur was knocked down by a powerful punch squarely on the face in the early round, getting up unsteadily to his footing on the eight count.
But the red-colored shorts of Arthur soon advanced again. Across the ring, the opponent - in opposing blue - was marked up soon, heavy swelling appearing under his eye as the fighters exchanged powerful shots.
The challenger, 27, connected with strong blows but Arthur, thirty-four, matched the intensity with stinging uppercuts as the pace hardly diminished over twelve rounds.
Arthur narrowly won the result with judges scorecards of even score, 115-113 and 115-112, but the two athletes were persistent and courageous, exactly what their hero Hatton stood for.
