British light heavyweight Joshua Buatsi secured a victory yet disappointing beginning to his career under new promoters with a decision win over Parker in Manchester.
The Olympic medal winner's activity level seemingly secured him a judges' verdict in a tight ten-round fight at the Co-op Live Arena.
But the challenger had his moments, connecting with powerful clean blows in a fight where the approaches never quite clicked, with excessive holding spoiling the contest.
The scoring judges judged it 96-94 for to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest performance but what do champions do? They succeed," Buatsi commented in the ring as he was faced disapproval from the audience.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the win but the British boxer experienced the second loss of his 28-match professional journey.
Buatsi Claims Triumph in Uneventful Match
His career development has stalled in the past few years through promotional disputes and considerable time of lack of fights.
Previously predicted as the rising talent of UK boxing, he now stands trying to fulfil that early promise - maybe in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with both competitors willing to take risks in a calculated initial rounds.
Parker, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand during the bout, was making just his second fight at the higher weight class.
By the fight's midpoint, the underdog had kept it close, making life awkward for the favorite, who operated with a protective stance to edge the more effective periods.
The spectators' acceptance wore thin because of frequent holding, with the challenger going down multiple occasions during grappling.
Parker finished the stronger, but many rounds were hard to judge. Nevertheless, previous titleholder Carl Frampton - providing analysis for Dazn - had it particularly wide for the challenger, scoring for Buatsi just a single round.
The victor advances, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Motivates Local Rivalry Battle
In the co-main event, Arthur defeated Rea by divided decision in a outstanding local rivalry battle to capture the European light heavyweight title.
The stadium grew hushed for a deeply poignant tribute before the fight as ten bells tolled in remembrance of local hero Ricky Hatton, who succumbed at age 46 in September.
It was the initial significant broadcast match card in the urban center since the passing of Hatton. As the final chime ended, the silence gave way to a roar of "there's just one Hatton".
The fighting during the bout reflected the feeling. The eventual winner was sent to the canvas by a significant blow squarely on the jaw in the second round, standing uncertainly to his footing on the eight count.
But the Manchester United-red shorts of the fighter soon advanced again. Across the ring, the opponent - in rival City blue - was damaged early, significant bruising appearing under his orbital area as the duo exchanged punishing blows.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with effective uppercuts as the pace hardly diminished over twelve rounds.
The victor edged the result with judges scorecards of even score, narrow lead and clearer margin, but the two athletes were persistent and brave, all the qualities their hero the legend embodied.
