UK 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 work rate seemingly secured him a split decision in a competitive ten-round fight at the Co-op Live Arena.
But the challenger had his moments, delivering effective clean blows in a contest where the styles didn't complement each other, with constant grabbing disrupting the fight.
The officials had it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my greatest performance but what defines champions? They succeed," the victor commented in the arena as he was greeted with negative reactions from the spectators.
The British fighter returned to winning ways after his initial pro loss - an epic battle with his previous opponent in February - to claim a twentieth professional win.
Some ringside observers thought Parker, thirty-one, deserved the decision but the Derbyshire fighter suffered the second loss of his 28-bout career.
The Champion Claims Victory in Dull Match
His career development has slowed in recent years through contract problems and considerable time of inactivity.
Once tipped as the rising talent of UK boxing, he now stands trying to realize his potential - maybe in what feels like a final roll of the dice - under fresh management.
He started carefully, with neither fighter willing to take risks in a cagey initial rounds.
The challenger, whose only previous defeat came at super middleweight against John Ryder in two years ago after damaging his hand in the contest, was participating in his second appearance at light-heavyweight.
By the middle rounds, the underdog had made it competitive, causing problems for Buatsi, who worked behind a tight guard to narrowly win the cleaner periods.
The crowd's patience decreased during regular grabbing, with the challenger going down several times during grappling.
The underdog finished the stronger, but several stanzas were hard to judge. Although, former world champion the boxing analyst - working with Dazn - had it particularly wide for the challenger, awarding Buatsi just a single round.
Buatsi progresses, but with the caliber of heavy hitter Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - on this evidence - still seems difficult.
Ricky Hatton Tribute Inspires Local Rivalry Battle
In the supporting bout, Arthur overcame Rea by divided decision in a excellent Manchester vs Manchester contest to secure the European light-heavyweight championship.
The venue fell silent for a profoundly moving homage ahead of the contest as 10 bells sounded in remembrance of Manchester's own Hatton, who succumbed at age 46 in September.
It was the first major televised fight night in the city since the passing of Hatton. As the final chime faded, the silence transitioned to a shout of "only one Ricky Hatton".
The competition during the bout reflected the sentiment. The eventual winner was sent to the canvas by a significant blow directly to the chin in the second round, rising shakily to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. Across the ring, the opponent - in opposing blue - was injured quickly, significant bruising forming under his eye as the pair traded hard punches.
Rea, twenty-seven, connected with strong blows but the champion, thirty-four, matched the intensity with stinging uppercuts as the pace hardly diminished over twelve rounds.
Arthur barely secured the result with scoring tallies of draw, close margin and wider gap, but the two athletes were relentless and brave, exactly what their inspiration the legend represented.
