British light-heavyweight Joshua Buatsi earned a win yet unimpressive debut to his career under fresh promotional backing with a points victory over Parker in Manchester.
The Olympic bronze medallist's activity level appeared to earn him a split decision in a close ten-round contest at the boxing arena.
But the challenger had his moments, delivering effective clean blows in a contest where the approaches failed to mesh, with constant grabbing marring the contest.
The officials scored it 96-94 for to Buatsi, with the third a even score.
"It wasn't my greatest showing but how do champions respond? They prevail," Buatsi stated in the ringside as he was faced disapproval from the crowd.
The Londoner returned to winning ways after his first professional defeat - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Various analysts believed the challenger, thirty-one, deserved the win but the contender suffered the second setback of his 28-match career.
Buatsi Claims Win in Dull Affair
Buatsi's progress has slowed in recent years through contract problems and considerable time of inactivity.
Earlier forecast as the next star of the British fight scene, he now finds himself trying to realize his potential - perhaps in what appears to be a last chance - under recent support.
He began cautiously, with neither fighter ready to overcommit in a calculated opening few rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury mid-fight, was participating in his second appearance at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, causing problems for Buatsi, who utilized a protective stance to edge the more effective periods.
The audience's tolerance decreased amid regular grabbing, with Parker going down various instances during close exchanges.
Parker finished the stronger, but multiple periods were challenging to assess. However, ex-champion the boxing analyst - commentating on Dazn - had it particularly wide for Parker, giving Buatsi just only one stanza.
The victor progresses, but with the presence of hard hitter Benavidez, and Russian champion Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Hatton Homage Fuels Manchester Derby Battle
In the supporting bout, Lyndon Arthur overcame Rea by split-decision in a terrific all-Manchester battle to capture the continental championship.
The venue became quiet for a extremely emotional tribute before the fight as 10 bells sounded in honor of local hero Ricky Hatton, who passed away at age 46 in recently.
It was the initial significant broadcast fight night in the urban center since Hatton's passing. As the concluding sound faded, the silence gave way to a shout of "only one Hatton".
The competition within the ring reflected the feeling. Arthur was knocked down by a left hook squarely on the face in the initial stage, rising shakily to his footing on the count of eight.
But the red-colored attire of Arthur soon came forward again. From the other corner, the opponent - in rival City blue - was injured quickly, heavy swelling forming under his orbital area as the duo exchanged powerful shots.
Rea, twenty-seven, landed power punches but the champion, thirty-four, matched the intensity with powerful upward punches as the intensity seldom decreased over 12 rounds.
The victor narrowly won the result with scoring tallies of even score, narrow lead and clearer margin, but the two athletes were determined and brave, exactly what their inspiration Hatton represented.
