UK light heavyweight Joshua Buatsi made a winning yet underwhelming start to life under recent management with a decision win over Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a competitive 10-round bout at the boxing arena.
But the challenger had his moments, landing some telling individual punches in a fight where the approaches didn't complement each other, with frequent clinching spoiling the fight.
The officials judged it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my finest showing but what defines champions? They win," Buatsi said in the ring as he was faced negative reactions from the spectators.
The Londoner returned to winning ways after his maiden career setback - an epic battle with Callum Smith in last winter - to secure a 20th career victory.
Various analysts felt the challenger, thirty-one, merited the win but the British boxer suffered the second defeat of his 28-match career.
Buatsi Earns Win in Uneventful Match
His career development has plateaued in recent times through promotional disputes and long spells of inactivity.
Previously predicted as the future of the British fight scene, he now stands trying to realize his potential - perhaps in what feels like a final roll of the dice - under recent support.
He opened tentatively, with both competitors prepared to take risks in a calculated initial rounds.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury in the contest, was participating in his second appearance at light heavyweight.
By the halfway stage, the underdog had made it competitive, causing problems for Buatsi, who utilized a tight guard to narrowly win the more effective rounds.
The audience's tolerance diminished during constant clinching, with the challenger going down multiple occasions during close exchanges.
The underdog ended stronger, but multiple periods were challenging to assess. Nevertheless, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just one round.
The victor moves on, but with the presence of power puncher Benavidez, and Russian champion Dmitry Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Homage Motivates Manchester Derby Fight
In the supporting bout, Lyndon Arthur beat Bradley Rea by divided decision in a excellent local rivalry battle to secure the European light heavyweight title.
The venue became quiet for a profoundly moving tribute prior to the bout as ten bells tolled in honor of local hero Ricky Hatton, who succumbed 46 years old in September.
It was the premier televised fight night in the location since Hatton's death. As the concluding sound faded, the stillness gave way to a roar of "only one Hatton".
The competition during the bout equaled the feeling. The eventual winner was knocked down by a powerful punch directly to the face in the initial stage, rising shakily to his footing on the count of eight.
But the red-colored attire of the fighter soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was marked up soon, heavy swelling developing under his orbital area as the fighters landed powerful shots.
The challenger, 27, connected with strong blows but the champion, 34, fought fire with fire with effective uppercuts as the action seldom decreased over the full distance.
The victor barely secured the result with scoring tallies of 114-114, narrow lead and wider gap, but each competitor were relentless and brave, exactly what their hero Hatton stood for.
