British light-heavyweight Joshua Buatsi made a winning yet unimpressive debut to life under recent management with a points victory over Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a majority decision in a competitive ten-round fight at the boxing arena.
But Parker found success, connecting with powerful clean blows in a fight where the approaches never quite clicked, with constant grabbing marring the contest.
Two judges had it 96-94 for to Buatsi, with the remaining official a 95-95.
"It wasn't my greatest showing but what do champions do? They win," Buatsi said in the arena as he was met by negative reactions from the spectators.
The British fighter bounced back after his first professional defeat - an memorable fight with his previous opponent in last winter - to earn a twentieth professional win.
Several boxing experts thought the challenger, thirty-one, deserved the decision but the Derbyshire fighter experienced the second defeat of his 28-fight professional journey.
Buatsi Earns Victory in Slow Encounter
The fighter's advancement has slowed in recent years through management issues and considerable time of inactivity.
Earlier forecast as the future of the British fight scene, he now is positioned trying to achieve expectations - possibly in what appears to be a last chance - under new promotional backing.
He started carefully, with neither fighter ready to be aggressive in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against John Ryder in 2022 after suffering a hand injury mid-fight, was making just his second bout at light heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who operated with a solid defense to barely take the cleaner rounds.
The crowd's patience wore thin during regular grabbing, with the challenger falling to the floor several times during grappling.
The underdog ended stronger, but multiple periods were difficult to score. However, previous titleholder the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just one round.
The victor moves on, but with the presence of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still looks steep.
Hatton Memorial Inspires All-Manchester Contest
In the co-main event, Lyndon Arthur overcame Bradley Rea by close verdict in a outstanding Manchester vs Manchester battle to win the continental championship.
The venue grew hushed for a extremely emotional tribute before the fight as ten bells rang in remembrance of local hero Hatton, who passed away aged 46 in last month.
It was the initial significant broadcast match card in the urban center since Hatton's death. As the concluding sound ended, the stillness gave way to a roar of "there's just one Hatton".
The action within the ring reflected the feeling. Arthur was floored by a powerful punch squarely on the chin in the initial stage, rising shakily to his footing on the referee's count.
But the traditional red shorts of Arthur soon pressed ahead again. Across the ring, the opponent - in rival City blue - was injured quickly, significant bruising developing under his face as the pair landed powerful shots.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with effective uppercuts as the pace rarely dropped over 12 rounds.
The victor narrowly won the verdict with judges scorecards of even score, close margin and clearer margin, but the two athletes were persistent and brave, everything their idol the legend represented.
