UK light-heavyweight Joshua Buatsi made a winning yet unimpressive debut to his career under recent management with a unanimous decision over Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a judges' verdict in a tight ten-round fight at the Co-op Live Arena.
But the challenger had his moments, landing some telling individual punches in a match where the styles didn't complement each other, with constant grabbing marring the contest.
The officials scored it 96-94 in favor to Buatsi, with the final judge a even score.
"It wasn't my finest showing but what do champions do? They succeed," Buatsi stated in the ringside as he was greeted with disapproval from the spectators.
The Londoner bounced back after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers felt the challenger, 31, merited the decision but the Derbyshire fighter experienced the second loss of his 28-fight career.
Buatsi Earns Triumph in Uneventful Encounter
Buatsi's progress has plateaued in recent years through promotional disputes and extended periods of inactivity.
Earlier forecast as the future of British boxing, he now stands trying to fulfil that early promise - perhaps in what appears to be a last chance - under fresh management.
He opened tentatively, with both competitors prepared to be aggressive in a calculated initial rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after damaging his hand during the bout, was participating in his second fight 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 spectators' acceptance wore thin during frequent holding, with the challenger slipping to the canvas several times during clinches.
The underdog ended stronger, but several stanzas were challenging to assess. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it particularly wide for Parker, awarding Buatsi just one round.
Buatsi progresses, but with the caliber of heavy hitter Benavidez, and Russian champion Bivol ruling the division, the journey to titles - judging by this showing - still appears challenging.
Hatton Homage Fuels Local Rivalry Fight
In the secondary fight, Arthur beat Bradley Rea by split-decision in a outstanding Manchester vs Manchester battle to win the continental belt.
The venue fell silent for a deeply poignant homage ahead of the contest as a bell ceremony sounded in memory of local hero Hatton, who succumbed at age 46 in recently.
It was the initial significant broadcast match card in the urban center since Hatton's death. As the final chime faded, the quiet became a shout of "only one Hatton".
The fighting during the bout equaled the emotion. The eventual winner was floored by a significant blow directly to the jaw in the early round, rising shakily to his footing on the referee's count.
But the red-colored attire of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was marked up quickly, heavy swelling developing under his eye as the duo exchanged hard punches.
The challenger, 27, landed power punches but Arthur, thirty-four, responded in kind with stinging uppercuts as the intensity rarely dropped over 12 rounds.
Arthur barely secured the decision with official scores of 114-114, 115-113 and 115-112, but both fighters were relentless and full of heart, all the qualities their inspiration the legend stood for.
