British light heavyweight Joshua Buatsi made a winning yet underwhelming beginning to his career under recent management with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a majority decision in a close ten-round contest at the boxing arena.
But Parker had his moments, delivering effective individual punches in a contest where the approaches didn't complement each other, with excessive holding spoiling the contest.
The scoring judges judged it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest showing but how do champions respond? They succeed," the victor commented in the ring as he was faced negative reactions from the crowd.
The Londoner returned to winning ways after his maiden career setback - an memorable fight with Callum Smith in February - to earn a 20th pro success.
Some ringside observers thought Parker, thirty-one, should have been awarded the victory but the Derbyshire fighter suffered the second loss of his 28-match career.
Buatsi Claims Triumph in Dull Affair
Buatsi's progress has stalled in recent times through management issues and long spells of inactivity.
Earlier forecast as the next star of UK boxing, he now is positioned trying to fulfil that early promise - possibly in what feels like a last chance - under fresh management.
He started carefully, with the two boxers ready to be aggressive in a calculated early stages.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in 2022 after breaking his hand mid-fight, was making just his second fight at light heavyweight.
By the middle rounds, the underdog had stayed in contention, causing problems for Buatsi, who operated with a protective stance to barely take the better rounds.
The spectators' acceptance diminished during constant clinching, with Parker going down multiple occasions during close exchanges.
The underdog ended stronger, but several stanzas were hard to judge. However, ex-champion the boxing analyst - working with the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
The victor progresses, but with the presence of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Hatton Homage Fuels Local Rivalry Fight
In the secondary fight, Lyndon Arthur defeated Rea by split-decision in a outstanding all-Manchester contest to capture the European light-heavyweight title.
The venue fell silent for a deeply poignant tribute prior to the bout as a bell ceremony tolled in remembrance of the city's native Hatton, who passed away 46 years old in recently.
It was the premier televised fight night in the city since the passing of Hatton. As the last bell disappeared, the stillness transitioned to a shout of "there's only one Ricky Hatton".
The fighting within the ring matched the emotion. Arthur was floored by a powerful punch squarely on the chin in the early round, standing uncertainly to his feet on the count of eight.
But the Manchester United-red shorts of Arthur soon advanced again. From the other corner, the opponent - in opposing blue - was injured early, noticeable damage forming under his eye as the pair exchanged hard punches.
Rea, 27, landed power punches but the champion, thirty-four, responded in kind with powerful upward punches as the intensity seldom decreased over the full distance.
Arthur narrowly won the result with scoring tallies of 114-114, narrow lead and wider gap, but each competitor were persistent and brave, everything their idol the legend represented.
