British light heavyweight Joshua Buatsi secured a victory yet unimpressive beginning to life under recent management with a unanimous decision over Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a competitive ten-round fight at the boxing arena.
But the challenger landed significant shots, landing some telling single shots in a fight where the techniques failed to mesh, with frequent clinching disrupting the contest.
Two judges scored it 96-94 in favor to Buatsi, with the remaining official a even score.
"It wasn't my finest showing but how do champions respond? They win," the victor commented in the ring as he was faced boos from the crowd.
The Londoner got back to winning after his first professional defeat - an epic battle with Callum Smith in last winter - to claim a 20th career victory.
Several boxing experts thought the challenger, thirty-one, merited the decision but the contender experienced the second defeat of his 28-fight career.
The Champion Earns Win in Uneventful Match
His career development has slowed in the past few years through promotional disputes and extended periods of inactivity.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to realize his potential - maybe in what feels like a ultimate opportunity - under fresh management.
He opened tentatively, with the two boxers prepared to be aggressive in a tentative opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in two years ago after suffering a hand injury mid-fight, was competing in only his second bout at the higher weight class.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who operated with a tight guard to narrowly win the more effective rounds.
The spectators' acceptance wore thin during constant clinching, with the challenger slipping to the canvas various instances during clinches.
The underdog closed well, but multiple periods were challenging to assess. Although, ex-champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, giving Buatsi just only one stanza.
Buatsi progresses, but with the likes of heavy hitter David Benavidez, and Russian champion Bivol ruling the division, the road to world glory - based on this performance - still appears challenging.
Hatton Homage Motivates All-Manchester Contest
In the supporting bout, Lyndon Arthur beat Rea by divided decision in a excellent local rivalry battle to win the European light-heavyweight title.
The venue became quiet for a deeply poignant tribute prior to the bout as ten bells tolled in memory of local hero Hatton, who passed away aged 46 in recently.
It was the initial significant broadcast match card in the city since Hatton's death. As the last bell faded, the silence became a shout of "only one Hatton".
The fighting during the bout reflected the emotion. Arthur was sent to the canvas by a powerful punch flush on the chin in the early round, rising shakily to his footing on the count of eight.
But the Manchester United-red equipment of Arthur soon pressed ahead again. From the other corner, the opponent - in rival City blue - was damaged early, heavy swelling appearing under his face as the duo traded punishing blows.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, fought fire with fire with powerful upward punches as the pace rarely dropped over 12 rounds.
Arthur barely secured the decision with official scores of even score, narrow lead and 115-112, but each competitor were persistent and brave, everything their idol Hatton embodied.
