British light-heavyweight Joshua Buatsi made a winning yet underwhelming start to his career under recent management with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a competitive 10-round bout at the boxing arena.
But Parker had his moments, delivering effective single shots in a contest where the techniques didn't complement each other, with frequent clinching disrupting the fight.
The scoring judges had it 96-94 for to Buatsi, with the third a 95-95 draw.
"It wasn't my finest display but how do champions respond? They prevail," Buatsi said in the ring as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an epic battle with his previous opponent in last winter - to earn a twentieth professional win.
Various analysts thought the challenger, thirty-one, merited the victory but the Derbyshire fighter endured the second defeat of his 28-fight professional journey.
The Champion Claims Victory in Dull Affair
His career development has slowed in recent times through promotional disputes and long spells of lack of fights.
Once tipped as the next star of UK boxing, he now stands trying to realize his potential - perhaps in what seems like a ultimate opportunity - under recent support.
He began cautiously, with the two boxers willing to be aggressive in a tentative early stages.
Parker, whose sole prior loss came at super middleweight against John Ryder in two years ago after suffering a hand injury mid-fight, was participating in his second fight at the higher weight class.
By the halfway stage, Parker had made it competitive, causing problems for Buatsi, who worked behind a tight guard to narrowly win the better periods.
The audience's tolerance decreased because of constant clinching, with the challenger going down several times during clinches.
The underdog closed well, but many rounds were hard to judge. However, former world champion Carl Frampton - working with the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just a single round.
The victor progresses, but with the presence of heavy hitter Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Tribute Motivates Manchester Derby Battle
In the secondary fight, Arthur overcame Bradley Rea by close verdict in a outstanding Manchester vs Manchester fight to secure the European light-heavyweight title.
The venue grew hushed for a deeply poignant tribute ahead of the contest as 10 bells tolled in honor of Manchester's own Hatton, who died aged 46 in last month.
It was the premier televised match card in the urban center since the passing of Hatton. As the concluding sound ended, the silence transitioned to a shout of "there's just one Ricky Hatton".
The competition during the bout reflected the feeling. The eventual winner was floored by a powerful punch squarely on the jaw in the second round, rising shakily to his position on the eight count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, Rea - in competitive blue - was marked up quickly, significant bruising appearing under his orbital area as the duo landed hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, thirty-four, responded in kind with powerful upward punches as the action rarely dropped over twelve rounds.
The victor edged the decision with judges scorecards of even score, close margin and wider gap, but both fighters were determined and courageous, all the qualities their inspiration Hatton embodied.
