British light-heavyweight Joshua Buatsi earned a win yet disappointing beginning to life under new promoters with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a competitive ten-round contest at the Co-op Live Arena.
But the challenger found success, landing some telling individual punches in a contest where the approaches failed to mesh, with frequent clinching marring the contest.
The officials scored it 96-94 for to the winner, with the third a 95-95 draw.
"It wasn't my greatest display but what defines champions? They win," the victor commented in the arena as he was faced negative reactions from the crowd.
The British fighter bounced back after his maiden career setback - an thrilling contest with his previous opponent in last winter - to claim a 20th pro success.
Several boxing experts thought Parker, thirty-one, should have been awarded the victory but the contender suffered the second setback of his 28-match professional journey.
The Champion Secures Triumph in Dull Encounter
The fighter's advancement has plateaued in recent years through management issues and considerable time of lack of fights.
Earlier forecast as the rising talent of UK boxing, he now stands trying to fulfil that early promise - perhaps in what appears to be a ultimate opportunity - under fresh management.
He started carefully, with neither fighter prepared to take risks in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against his former opponent in two years ago after damaging his hand during the bout, was making just his second fight at light-heavyweight.
By the fight's midpoint, the underdog had stayed in contention, making life awkward for Buatsi, who operated with a solid defense to edge the cleaner rounds.
The crowd's patience wore thin amid constant clinching, with Parker going down various instances during close exchanges.
The underdog finished the stronger, but several stanzas were challenging to assess. Although, ex-champion Carl Frampton - working with the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just only one stanza.
Buatsi moves on, but with the presence of heavy hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Fuels Local Rivalry Contest
In the secondary fight, Arthur defeated Rea by close verdict in a excellent local rivalry fight to secure the continental title.
The venue fell silent for a extremely emotional memorial ahead of the contest as a bell ceremony tolled in remembrance of Manchester's own Ricky Hatton, who passed away at age 46 in September.
It was the first major televised match card in the location since Hatton's passing. As the last bell disappeared, the quiet gave way to a chant of "only one Ricky Hatton".
The fighting inside the ropes equaled the feeling. The eventual winner was floored by a significant blow squarely on the jaw in the early round, standing uncertainly to his position on the count of eight.
But the red-colored equipment of the fighter soon pressed ahead again. Across the ring, Rea - in competitive blue - was damaged quickly, noticeable damage developing under his eye as the duo exchanged punishing blows.
The challenger, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with powerful upward punches as the intensity seldom decreased over twelve rounds.
Arthur edged the decision with scoring tallies of even score, narrow lead and 115-112, but both fighters were persistent and full of heart, everything their inspiration the legend stood for.
