British light heavyweight Joshua Buatsi made a winning yet underwhelming debut to his career under recent management with a decision win over Parker in Manchester.
The Olympic medal winner's activity level seemingly secured him a majority decision in a close ten-round bout at the Co-op Live Arena.
But the challenger landed significant shots, landing some telling individual punches in a match where the techniques didn't complement each other, with constant grabbing spoiling the fight.
The scoring judges judged it 96-94 for to Buatsi, with the third a even score.
"It wasn't my greatest performance but what defines champions? They succeed," the victor stated in the ring as he was faced disapproval from the crowd.
The Londoner bounced back after his maiden career setback - an epic battle with Callum Smith in February - to earn a 20th career victory.
Several boxing experts felt the challenger, 31, should have been awarded the decision but the British boxer experienced the second defeat of his 28-bout professional journey.
Buatsi Secures Win in Uneventful Encounter
His career development has slowed in recent years through contract problems and extended periods of inactivity.
Previously predicted as the future of UK boxing, he now is positioned trying to achieve expectations - possibly in what feels like a last chance - under recent support.
He started carefully, with the two boxers willing to take risks in a calculated opening few rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in 2022 after damaging his hand in the contest, was participating in his second fight at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for the favorite, who utilized a tight guard to barely take the better stanzas.
The spectators' acceptance decreased amid constant clinching, with Parker falling to the floor various instances during grappling.
The underdog closed well, but multiple periods were challenging to assess. However, previous titleholder Carl Frampton - providing analysis for Dazn - had it particularly wide for the challenger, scoring for Buatsi just a single round.
Buatsi moves on, but with the caliber of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the path to championship success - on this evidence - still looks steep.
Ricky Hatton Homage Motivates All-Manchester Contest
In the secondary fight, Arthur beat Rea by close verdict in a outstanding Manchester vs Manchester contest to win the European light-heavyweight belt.
The arena became quiet for a deeply poignant memorial ahead of the contest as ten bells sounded in honor of Manchester's own Ricky Hatton, who died at age 46 in last month.
It was the initial significant broadcast fight night in the location since Hatton's passing. As the final chime faded, the silence became a chant of "there's only one Ricky Hatton".
The competition during the bout matched the emotion. The eventual winner was knocked down by a significant blow directly to the face in the second round, getting up unsteadily to his position on the count of eight.
But the Manchester United-red equipment of the fighter soon came forward again. On the opposite side, Rea - in competitive blue - was damaged quickly, noticeable damage appearing under his orbital area as the pair traded hard punches.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the intensity seldom decreased over 12 rounds.
The victor narrowly won the decision with scoring tallies of 114-114, narrow lead and clearer margin, but the two athletes were persistent and full of heart, exactly what their idol Hatton stood for.
