British light-heavyweight Joshua Buatsi secured a victory yet underwhelming beginning to life under recent management with a decision win over Parker in Manchester.
The Olympic medal winner's punch output likely gained him a majority decision in a tight ten-round fight at the Co-op Live Arena.
But the challenger had his moments, delivering effective clean blows in a contest where the techniques didn't complement each other, with frequent clinching marring the fight.
The officials judged it 96-94 for to Buatsi, with the final judge a 95-95.
"It wasn't my finest showing but how do champions respond? They prevail," Buatsi said in the ringside as he was greeted with negative reactions from the spectators.
The British fighter got back to winning after his maiden career setback - an thrilling contest with his previous opponent in last winter - to secure a 20th career victory.
Some ringside observers felt the challenger, thirty-one, should have been awarded the decision but the Derbyshire fighter experienced the second defeat of his 28-bout career.
The Champion Earns Victory in Uneventful Encounter
Buatsi's progress has stalled in recent times through contract problems and considerable time of inactivity.
Once tipped as the next star of British boxing, he now stands trying to achieve expectations - maybe in what appears to be a last chance - under recent support.
He started carefully, with the two boxers prepared to be aggressive in a tentative opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand in the contest, was competing in only his second fight at the higher weight class.
By the fight's midpoint, Parker had kept it close, making life awkward for Buatsi, who utilized a tight guard to narrowly win the more effective stanzas.
The crowd's patience decreased during constant clinching, with the challenger going down multiple occasions during close exchanges.
Parker ended stronger, but several stanzas were challenging to assess. However, previous titleholder Carl Frampton - working with the broadcast network - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
The victor advances, but with the caliber of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the path to championship success - judging by this showing - still seems difficult.
Hatton Tribute Motivates Local Rivalry Fight
In the supporting bout, Arthur overcame Rea by split-decision in a excellent Manchester vs Manchester contest to secure the continental championship.
The stadium became quiet for a extremely emotional tribute ahead of the contest as a bell ceremony tolled in honor of Manchester's own Ricky Hatton, who succumbed at age 46 in recently.
It was the premier televised boxing event in the city since Hatton's passing. As the final chime ended, the stillness gave way to a roar of "there's only one Hatton".
The action inside the ropes reflected the emotion. The eventual winner was knocked down by a left hook flush on the chin in the initial stage, standing uncertainly to his position on the eight count.
But the traditional red attire of Arthur soon advanced again. From the other corner, the opponent - in competitive blue - was damaged early, heavy swelling developing under his eye as the fighters landed punishing blows.
The challenger, 27, connected with strong blows but Arthur, 34, responded in kind with powerful upward punches as the pace rarely dropped over twelve rounds.
Arthur barely secured the decision with scoring tallies of even score, narrow lead and clearer margin, but each competitor were determined and courageous, exactly what their hero the legend stood for.
