British light-heavyweight Joshua Buatsi made a winning yet disappointing debut to his career under new promoters with a decision win over Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a judges' verdict in a tight ten-round contest at the Co-op Live Arena.
But the challenger had his moments, landing some telling single shots in a fight where the techniques didn't complement each other, with constant grabbing disrupting the contest.
The scoring judges judged it 96-94 to the winner, with the third a 95-95.
"It wasn't my best showing but what defines champions? They prevail," Buatsi commented in the ringside as he was faced disapproval from the audience.
The Londoner got back to winning after his maiden career setback - an memorable fight with Callum Smith in last winter - to claim a 20th pro success.
Some ringside observers believed the challenger, thirty-one, deserved the decision but the Derbyshire fighter suffered the second loss of his 28-bout professional journey.
The Champion Secures Triumph in Dull Encounter
Buatsi's progress has stalled in the past few years through contract problems and long spells of inactivity.
Earlier forecast as the future of British boxing, he now finds himself trying to achieve expectations - perhaps in what feels like a final roll of the dice - under recent support.
He began cautiously, with the two boxers willing to be aggressive in a calculated initial rounds.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in two years ago after breaking his hand in the contest, was making just his second fight at the higher weight class.
By the halfway stage, the underdog had made it competitive, making life awkward for Buatsi, who utilized a solid defense to edge the cleaner rounds.
The spectators' acceptance wore thin amid frequent holding, with Parker falling to the floor several times during clinches.
Parker closed well, but many rounds were difficult to score. Although, former world champion Carl Frampton - commentating on Dazn - had it significantly in favor for the challenger, giving Buatsi just a single round.
Buatsi advances, but with the caliber of power puncher Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the journey to titles - judging by this showing - still appears challenging.
Hatton Homage Inspires All-Manchester Fight
In the secondary fight, Arthur defeated Bradley Rea by split-decision in a terrific all-Manchester contest to secure the continental title.
The venue grew hushed for a profoundly moving tribute before the fight as a bell ceremony tolled in honor of Manchester's own Ricky Hatton, who succumbed aged 46 in recently.
It was the first major televised match card in the urban center since the passing of Hatton. As the final chime disappeared, the quiet transitioned to a roar of "only one Ricky Hatton".
The competition within the ring equaled the feeling. Arthur was sent to the canvas by a powerful punch squarely on the chin in the second round, getting up unsteadily to his feet on the referee's count.
But the red-colored equipment of the fighter soon advanced again. On the opposite side, the opponent - in rival City blue - was injured quickly, noticeable damage developing under his face as the pair traded hard punches.
The challenger, 27, connected with strong blows but the champion, thirty-four, matched the intensity with effective uppercuts as the action hardly diminished over 12 rounds.
The victor barely secured the result with official scores of even score, narrow lead and 115-112, but both fighters were persistent and courageous, exactly what their hero the legend stood for.
