British light-heavyweight Joshua Buatsi made a winning yet disappointing start to his career under fresh promotional backing with a points victory over Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a judges' verdict in a competitive ten-round bout at the Manchester venue.
But Parker landed significant shots, connecting with powerful single shots in a match where the approaches failed to mesh, with frequent clinching spoiling the action.
The officials scored it 96-94 for to the winner, with the third a even score.
"It wasn't my greatest display but what do champions do? They prevail," Buatsi commented in the ring as he was met by negative reactions from the audience.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in last winter - to claim a 20th pro success.
Several boxing experts felt the challenger, thirty-one, deserved the victory but the Derbyshire fighter experienced the second loss of his 28-fight career.
Buatsi Claims Win in Dull Affair
His career development has plateaued in recent times through contract problems and extended periods of lack of fights.
Once tipped as the next star of UK boxing, he now stands trying to fulfil that early promise - perhaps in what appears to be a last chance - under new promotional backing.
He opened tentatively, with both competitors ready to overcommit in a calculated initial rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in two years ago after suffering a hand injury during the bout, was competing in only his second bout at light heavyweight.
By the middle rounds, the underdog had stayed in contention, causing problems for Buatsi, who utilized a protective stance to edge the cleaner periods.
The audience's tolerance wore thin during constant clinching, with the challenger falling to the floor various instances during clinches.
The underdog closed well, but many rounds were hard to judge. However, previous titleholder the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, awarding Buatsi just a single round.
The victor advances, but with the presence of heavy hitter David Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - judging by this showing - still appears challenging.
Ricky Hatton Tribute Inspires Local Rivalry Fight
In the co-main event, Arthur beat Rea by close verdict in a excellent Manchester vs Manchester contest to capture the European light-heavyweight title.
The stadium fell silent for a extremely emotional memorial before the fight as a bell ceremony tolled in remembrance of local hero Hatton, who succumbed aged 46 in September.
It was the premier televised boxing event in the city since the passing of Hatton. As the final chime disappeared, the stillness became a roar of "there's just one Hatton".
The action inside the ropes equaled the feeling. The eventual winner was sent to the canvas by a powerful punch directly to the jaw in the initial stage, standing uncertainly to his footing on the count of eight.
But the traditional red shorts of Arthur soon pressed ahead again. On the opposite side, Rea - in opposing blue - was marked up quickly, noticeable damage appearing under his face as the fighters exchanged hard punches.
The challenger, twenty-seven, delivered effective strikes but the champion, thirty-four, responded in kind with stinging uppercuts as the intensity rarely dropped over 12 rounds.
The victor narrowly won the result with scoring tallies of even score, close margin and 115-112, but each competitor were relentless and full of heart, everything their idol Hatton represented.
