British light heavyweight Joshua Buatsi made a winning yet unimpressive start to his career under new promoters with a points victory over Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a majority decision in a close ten-round fight at the Co-op Live Arena.
But the challenger found success, landing some telling single shots in a match where the techniques didn't complement each other, with excessive holding spoiling the contest.
The scoring judges scored it 96-94 to the winner, with the third a 95-95.
"It wasn't my greatest showing but what do champions do? They win," the victor stated in the arena as he was faced boos from the audience.
The Londoner returned to winning ways after his first professional defeat - an epic battle with Callum Smith in February - to secure a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the victory but the Derbyshire fighter endured the second loss of his 28-fight professional journey.
Buatsi Earns Win in Dull Affair
His career development has stalled in recent years through contract problems and long spells of inactivity.
Earlier forecast as the next star of the British fight scene, he now is positioned trying to fulfil that early promise - possibly in what seems like a last chance - under new promotional backing.
He started carefully, with neither fighter ready to take risks in a tentative opening few rounds.
The challenger, whose only previous defeat came at super middleweight against John Ryder in 2022 after suffering a hand injury mid-fight, was participating in his second appearance at the higher weight class.
By the halfway stage, the underdog had stayed in contention, creating difficulties for the favorite, who utilized a tight guard to narrowly win the more effective stanzas.
The crowd's patience decreased during constant clinching, with Parker slipping to the canvas various instances during clinches.
Parker closed well, but multiple periods were challenging to assess. Nevertheless, former world champion Carl Frampton - providing analysis for Dazn - had it strongly leaning for the challenger, giving Buatsi just a single round.
The victor advances, but with the caliber of heavy hitter David Benavidez, and Russian star Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Hatton Tribute Inspires Local Rivalry Contest
In the co-main event, Lyndon Arthur overcame Bradley Rea by divided decision in a outstanding all-Manchester contest to win the European light heavyweight belt.
The venue fell silent for a extremely emotional memorial ahead of the contest as 10 bells sounded in memory of local hero Hatton, who succumbed at age 46 in September.
It was the premier televised boxing event in the urban center since Hatton's death. As the concluding sound faded, the stillness transitioned to a shout of "there's just one Hatton".
The fighting within the ring equaled the sentiment. The eventual winner was floored by a powerful punch directly to the chin in the initial stage, getting up unsteadily to his feet on the referee's count.
But the Manchester United-red equipment of the fighter soon advanced again. On the opposite side, the opponent - in rival City blue - was injured quickly, significant bruising appearing under his eye as the pair exchanged punishing blows.
The challenger, twenty-seven, delivered effective strikes but Arthur, 34, responded in kind with stinging uppercuts as the pace rarely dropped over twelve rounds.
The victor narrowly won the result with official scores of 114-114, close margin and wider gap, but each competitor were persistent and courageous, everything their inspiration Hatton represented.
