British light heavyweight Joshua Buatsi made a winning yet disappointing beginning to his career under fresh promotional backing with a points victory over Parker in Manchester.
The Olympic bronze medallist's punch output appeared to earn him a judges' verdict in a close 10-round contest at the boxing arena.
But the challenger landed significant shots, connecting with powerful clean blows in a match where the approaches didn't complement each other, with frequent clinching marring the contest.
The officials scored it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my greatest showing but how do champions respond? They win," Buatsi stated in the ringside as he was met by disapproval from the crowd.
The British fighter bounced back after his maiden career setback - an thrilling contest with his previous opponent in February - to claim a 20th career victory.
Several boxing experts felt Parker, thirty-one, merited the victory but the contender experienced the second setback of his 28-bout career.
Buatsi Claims Triumph in Uneventful Match
His career development has stalled in recent times through contract problems and extended periods of inactivity.
Earlier forecast as the future of UK boxing, he now finds himself trying to achieve expectations - possibly in what appears to be a last chance - under recent support.
He opened tentatively, with both competitors prepared to overcommit in a calculated opening few rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in 2022 after breaking his hand during the bout, was competing in only his second fight at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, causing problems for the favorite, who utilized a tight guard to narrowly win the cleaner stanzas.
The spectators' acceptance wore thin during regular grabbing, with the challenger falling to the floor several times during close exchanges.
The underdog ended stronger, but multiple periods were difficult to score. Nevertheless, ex-champion the boxing analyst - commentating on Dazn - had it significantly in favor for the challenger, scoring for Buatsi just a single round.
The victor moves on, but with the likes of heavy hitter David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still appears challenging.
Hatton Tribute Inspires Local Rivalry Contest
In the co-main event, Lyndon Arthur defeated Bradley Rea by close verdict in a outstanding Manchester vs Manchester fight to capture the continental championship.
The arena fell silent for a deeply poignant memorial prior to the bout as ten bells sounded in remembrance of local hero Ricky Hatton, who passed away 46 years old in recently.
It was the first major televised boxing event in the location since Hatton's passing. As the last bell ended, the stillness gave way to a chant of "only one Hatton".
The fighting within the ring equaled the emotion. The eventual winner was knocked down by a significant blow squarely on the face in the initial stage, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of Arthur soon advanced again. On the opposite side, the opponent - in opposing blue - was injured quickly, heavy swelling forming under his orbital area as the pair traded hard punches.
Rea, 27, connected with strong blows but the champion, 34, responded in kind with stinging uppercuts as the action rarely dropped over the full distance.
Arthur edged the verdict with scoring tallies of draw, 115-113 and 115-112, but the two athletes were persistent and full of heart, all the qualities their idol the legend stood for.
