UK light-heavyweight Joshua Buatsi made a winning yet underwhelming start to life under recent management with a decision win over Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a competitive ten-round bout at the Manchester venue.
But the challenger landed significant shots, delivering effective individual punches in a match where the techniques didn't complement each other, with frequent clinching marring the action.
The scoring judges scored it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my best performance but how do champions respond? They prevail," Buatsi said in the ring as he was met by disapproval from the audience.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in February - to claim a 20th career victory.
Some ringside observers believed Parker, thirty-one, should have been awarded the win but the Derbyshire fighter suffered the second setback of his 28-bout professional journey.
Buatsi Earns Triumph in Uneventful Match
The fighter's advancement has stalled in recent times through contract problems and long spells of inactivity.
Once tipped as the future of the British fight scene, he now finds himself trying to realize his potential - perhaps in what feels like a final roll of the dice - under new promotional backing.
He started carefully, with the two boxers prepared to overcommit in a cagey initial rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in two years ago after damaging his hand in the contest, was participating in his second bout at light heavyweight.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who utilized a protective stance to narrowly win the more effective stanzas.
The crowd's patience diminished during constant clinching, with Parker falling to the floor multiple occasions during clinches.
The underdog ended stronger, but multiple periods were challenging to assess. However, former world champion Carl Frampton - working with Dazn - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
The victor moves on, but with the caliber of heavy hitter Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Motivates Manchester Derby Contest
In the secondary fight, Arthur overcame Bradley Rea by divided decision in a outstanding Manchester vs Manchester battle to capture the continental belt.
The stadium fell silent for a deeply poignant homage prior to the bout as ten bells rang in remembrance of local hero Ricky Hatton, who succumbed at age 46 in last month.
It was the premier televised fight night in the city since Hatton's death. As the last bell faded, the silence gave way to a shout of "only one Ricky Hatton".
The fighting during the bout reflected the sentiment. The eventual winner was sent to the canvas by a powerful punch squarely on the chin in the initial stage, standing uncertainly to his footing on the referee's count.
But the traditional red equipment of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was marked up quickly, significant bruising forming under his face as the fighters traded hard punches.
The challenger, twenty-seven, landed power punches but Arthur, 34, matched the intensity with powerful upward punches as the pace rarely dropped over twelve rounds.
Arthur barely secured the result with official scores of even score, close margin and clearer margin, but both fighters were determined and brave, all the qualities their inspiration the legend stood for.
