UK light-heavyweight Joshua Buatsi made a winning yet unimpressive beginning to his career under recent management with a unanimous decision over Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a tight 10-round fight at the Co-op Live Arena.
But Parker landed significant shots, delivering effective clean blows in a contest where the techniques failed to mesh, with frequent clinching spoiling the action.
The scoring judges scored it 96-94 for to the winner, with the remaining official a 95-95.
"It wasn't my greatest performance but what defines champions? They prevail," the victor commented in the arena as he was met by disapproval from the crowd.
The British fighter returned to winning ways after his maiden career setback - an epic battle with Callum Smith in February - to earn a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the decision but the contender experienced the second setback of his 28-fight career.
Buatsi Secures Triumph in Uneventful Affair
The fighter's advancement has plateaued in recent years through contract problems and long spells of inactivity.
Earlier forecast as the next star of the British fight scene, he now finds himself trying to achieve expectations - perhaps in what feels like a final roll of the dice - under new promotional backing.
He opened tentatively, with the two boxers prepared to take risks in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after damaging his hand during the bout, was participating in his second bout at light-heavyweight.
By the halfway stage, the underdog had stayed in contention, making life awkward for Buatsi, who utilized a tight guard to narrowly win the better periods.
The crowd's patience wore thin amid constant clinching, with the challenger going down various instances during clinches.
The underdog closed well, but many rounds were difficult to score. Nevertheless, former world champion the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
Buatsi moves on, but with the caliber of power puncher Benavidez, and Russian star Dmitry Bivol ruling the division, the road to world glory - on this evidence - still appears challenging.
Hatton Homage Fuels Local Rivalry Fight
In the co-main event, Lyndon Arthur beat Bradley Rea by divided decision in a terrific all-Manchester fight to win the European light-heavyweight belt.
The stadium became quiet for a extremely emotional tribute ahead of the contest as ten bells rang in honor of local hero Hatton, who died 46 years old in September.
It was the premier televised match card in the location since Hatton's passing. As the final chime disappeared, the quiet became a shout of "only one Ricky Hatton".
The competition within the ring equaled the feeling. The eventual winner was sent to the canvas by a powerful punch squarely on the face in the second round, rising shakily to his footing on the count of eight.
But the red-colored attire of the fighter soon pressed ahead again. Across the ring, the opponent - in competitive blue - was damaged quickly, noticeable damage forming under his eye as the duo landed powerful shots.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with stinging uppercuts as the intensity rarely dropped over 12 rounds.
Arthur narrowly won the result with judges scorecards of draw, close margin and 115-112, but both fighters were relentless and full of heart, all the qualities their idol Hatton stood for.
