British light-heavyweight Joshua Buatsi made a winning yet underwhelming start to his career under recent management with a points victory over Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a split decision in a tight ten-round bout at the Manchester venue.
But the challenger landed significant shots, delivering effective single shots in a contest where the techniques never quite clicked, with excessive holding marring the fight.
Two judges scored it 96-94 for to Buatsi, with the third a even score.
"It wasn't my greatest showing but how do champions respond? They prevail," Buatsi said in the arena as he was met by disapproval from the crowd.
The Londoner got back to winning after his initial pro loss - an memorable fight with Callum Smith in February - to secure a 20th career victory.
Several boxing experts believed the challenger, thirty-one, deserved the victory but the contender endured the second loss of his 28-match professional journey.
Buatsi Claims Triumph in Dull Match
His career development has plateaued in the past few years through promotional disputes and extended periods of lack of fights.
Earlier forecast as the next star of the British fight scene, he now finds himself trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under fresh management.
He began cautiously, with both competitors willing to overcommit in a tentative initial rounds.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in 2022 after breaking his hand during the bout, was making just his second bout at light-heavyweight.
By the halfway stage, the underdog had kept it close, causing problems for Buatsi, who utilized a protective stance to edge the better stanzas.
The crowd's patience diminished because of frequent holding, with the challenger falling to the floor various instances during close exchanges.
Parker closed well, but several stanzas were difficult to score. Nevertheless, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just only one stanza.
Buatsi advances, but with the likes of hard hitter Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Tribute Inspires Manchester Derby Fight
In the co-main event, Lyndon Arthur defeated Bradley Rea by split-decision in a excellent Manchester vs Manchester contest to capture the European light heavyweight championship.
The stadium became quiet for a deeply poignant tribute before the fight as a bell ceremony tolled in remembrance of local hero Ricky Hatton, who succumbed 46 years old in September.
It was the first major televised boxing event in the urban center since Hatton's passing. As the last bell faded, the silence transitioned to a shout of "there's only one Hatton".
The fighting inside the ropes equaled the emotion. The eventual winner was floored by a powerful punch flush on the face in the second round, getting up unsteadily to his position on the eight count.
But the traditional red equipment of the fighter soon pressed ahead again. From the other corner, the opponent - in opposing blue - was marked up soon, heavy swelling developing under his eye as the fighters traded hard punches.
Rea, 27, connected with strong blows but Arthur, 34, matched the intensity with effective uppercuts as the intensity hardly diminished over the full distance.
Arthur barely secured the result with judges scorecards of even score, 115-113 and wider gap, but each competitor were relentless and brave, all the qualities their hero Hatton stood for.
