British light-heavyweight Joshua Buatsi secured a victory yet unimpressive start to life under recent management with a points victory over Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a split decision in a competitive ten-round fight at the Co-op Live Arena.
But the challenger found success, landing some telling clean blows in a contest where the approaches didn't complement each other, with excessive holding marring the action.
The officials judged it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my finest showing but what do champions do? They prevail," Buatsi commented in the ring as he was met by disapproval from the audience.
The Londoner got back to winning after his maiden career setback - an epic battle with his previous opponent in February - to earn a twentieth professional win.
Various analysts thought the challenger, thirty-one, should have been awarded the win but the British boxer suffered the second loss of his 28-match professional journey.
Buatsi Claims Triumph in Dull Encounter
The fighter's advancement has stalled in recent years through promotional disputes and long spells of inactivity.
Previously predicted as the future of the British fight scene, he now stands trying to fulfil that early promise - perhaps in what seems like a last chance - under recent support.
He began cautiously, with the two boxers prepared to take risks in a tentative initial rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in 2022 after suffering a hand injury in the contest, was competing in only his second fight at light heavyweight.
By the middle rounds, the underdog had made it competitive, causing problems for Buatsi, who utilized a solid defense to barely take the better stanzas.
The spectators' acceptance diminished amid regular grabbing, with Parker going down several times during grappling.
The underdog finished the stronger, but multiple periods were difficult to score. However, former world champion Carl Frampton - working with Dazn - had it strongly leaning for the challenger, scoring for Buatsi just one round.
Buatsi progresses, but with the caliber of heavy hitter Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Hatton Memorial Inspires All-Manchester Fight
In the co-main event, Arthur defeated Rea by split-decision in a excellent all-Manchester fight to secure the European light-heavyweight championship.
The arena became quiet for a deeply poignant homage ahead of the contest as 10 bells tolled in memory of the city's native Hatton, who succumbed at age 46 in September.
It was the premier televised boxing event in the location since the passing of Hatton. As the last bell disappeared, the silence transitioned to a roar of "there's only one Hatton".
The competition inside the ropes reflected the emotion. Arthur was knocked down by a powerful punch squarely on the face in the initial stage, standing uncertainly to his footing on the count of eight.
But the traditional red equipment of Arthur soon advanced again. On the opposite side, the opponent - in competitive blue - was marked up soon, noticeable damage developing under his eye as the pair landed punishing blows.
The challenger, twenty-seven, delivered effective strikes but Arthur, 34, matched the intensity with effective uppercuts as the pace hardly diminished over the full distance.
Arthur edged the result with official scores of even score, 115-113 and clearer margin, but both fighters were persistent and courageous, all the qualities their idol Hatton represented.
