British light heavyweight Joshua Buatsi made a winning yet underwhelming debut to his career under recent management with a decision win over Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a majority decision in a competitive ten-round bout at the boxing arena.
But the challenger landed significant shots, delivering effective individual punches in a fight where the techniques didn't complement each other, with constant grabbing marring the fight.
The officials judged it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my best display but what defines champions? They prevail," Buatsi said in the ringside as he was met by boos from the spectators.
The Londoner got back to winning after his first professional defeat - an thrilling contest with Callum Smith in last winter - to claim a twentieth professional win.
Various analysts believed Parker, 31, merited the decision but the contender experienced the second setback of his 28-bout career.
Buatsi Secures Triumph in Uneventful Match
His career development has stalled in recent times through promotional disputes and considerable time of inactivity.
Earlier forecast as the next star of UK boxing, he now finds himself trying to achieve expectations - perhaps in what feels like a last chance - under recent support.
He began cautiously, with both competitors ready to overcommit in a calculated early stages.
Parker, whose only previous defeat came at the lower weight class against John Ryder in 2022 after damaging his hand during the bout, was participating in his second bout at the higher weight class.
By the middle rounds, the underdog had stayed in contention, causing problems for the favorite, who operated with a tight guard to narrowly win the cleaner periods.
The crowd's patience wore thin because of frequent holding, with Parker going down multiple occasions during grappling.
Parker finished the stronger, but multiple periods were hard to judge. However, former world champion the boxing analyst - commentating on the broadcast network - had it particularly wide for the challenger, awarding Buatsi just one round.
The victor moves on, but with the likes of heavy hitter Benavidez, and Russian champion Dmitry Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Memorial Inspires Manchester Derby Battle
In the secondary fight, Arthur defeated Bradley Rea by divided decision in a terrific local rivalry battle to capture the European light heavyweight championship.
The arena became quiet for a extremely emotional homage before the fight as a bell ceremony tolled in remembrance of local hero Ricky Hatton, who passed away at age 46 in last month.
It was the first major televised boxing event in the location since the passing of Hatton. As the last bell faded, the silence transitioned to a shout of "there's only one Ricky Hatton".
The fighting within the ring reflected the sentiment. Arthur was floored by a significant blow flush on the face in the second round, rising shakily to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon advanced again. Across the ring, Rea - in opposing blue - was damaged early, noticeable damage developing under his face as the duo traded powerful shots.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with stinging uppercuts as the intensity rarely dropped over 12 rounds.
The victor narrowly won the result with judges scorecards of 114-114, narrow lead and wider gap, but both fighters were relentless and brave, exactly what their idol Hatton embodied.
