British light-heavyweight Joshua Buatsi secured a victory yet underwhelming beginning to his career under recent management with a decision win over Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a judges' verdict in a close ten-round fight at the Co-op Live Arena.
But the challenger had his moments, landing some telling individual punches in a contest where the approaches failed to mesh, with frequent clinching disrupting the fight.
The scoring judges scored it 96-94 for to Buatsi, with the third a 95-95.
"It wasn't my greatest display but how do champions respond? They succeed," Buatsi commented in the ringside as he was greeted with disapproval from the crowd.
The British fighter returned to winning ways after his initial pro loss - an epic battle with his previous opponent in last winter - to claim a twentieth professional win.
Several boxing experts thought Parker, thirty-one, merited the decision but the contender suffered the second loss of his 28-bout career.
Buatsi Claims Victory in Slow Affair
Buatsi's progress has slowed in recent years through management issues and long spells of inactivity.
Earlier forecast as the future of UK boxing, he now is positioned trying to fulfil that early promise - possibly in what seems like a ultimate opportunity - under recent support.
He began cautiously, with neither fighter prepared to take risks in a cagey early stages.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in 2022 after damaging his hand during the bout, was competing in only his second fight at the higher weight class.
By the halfway stage, Parker had kept it close, causing problems for the favorite, who utilized a solid defense to narrowly win the cleaner periods.
The spectators' acceptance wore thin because of constant clinching, with the challenger going down various instances during clinches.
The underdog ended stronger, but many rounds were hard to judge. Nevertheless, previous titleholder Carl Frampton - providing analysis for Dazn - had it particularly wide for Parker, scoring for Buatsi just one round.
The victor moves on, but with the likes of power puncher Benavidez, and Eastern European fighter Bivol dominating the weight class, the road to world glory - judging by this showing - still looks steep.
Hatton Homage Motivates Local Rivalry Battle
In the supporting bout, Arthur beat Rea by divided decision in a terrific local rivalry fight to secure the European light-heavyweight belt.
The arena fell silent for a extremely emotional memorial before the fight as 10 bells tolled in memory of Manchester's own Hatton, who died aged 46 in last month.
It was the premier televised match card in the city since the passing of Hatton. As the final chime ended, the stillness became a roar of "there's just one Hatton".
The fighting during the bout equaled the feeling. Arthur was knocked down by a left hook squarely on the jaw in the initial stage, rising shakily to his feet on the eight count.
But the red-colored equipment of the fighter soon came forward again. On the opposite side, the opponent - in competitive blue - was marked up quickly, noticeable damage appearing under his face as the duo exchanged hard punches.
The challenger, 27, delivered effective strikes but Arthur, thirty-four, matched the intensity with powerful upward punches as the intensity seldom decreased over twelve rounds.
The victor edged the result with official scores of 114-114, close margin and wider gap, but each competitor were persistent and full of heart, everything their inspiration the legend represented.
