Zach Parker’s long-awaited fight for the WBO’s interim super middleweight title was finally made official Friday afternoon in London.

Parker and John Ryder both made weight for this 12-round, 168-pound battle between Brits, which will headline a show Saturday night at O2 Arena in London.

Parker (22-0, 16 KOs) stepped on the British Boxing Board of Control’s scale at 167.3 pounds. Ryder (31-5, 17 KOs), a southpaw who has held the WBA interim super middleweight title, officially weighed in slightly lighter, at 167 pounds.

BT Sport 1 will televise the card headlined by Parker-Ryder in the United Kingdom and Ireland (7 p.m. GMT). It’ll be streamed by ESPN+ in the United States (2 p.m. ET; 11 a.m. PT).

Woodville’s Parker, 28, is the WBO’s number one-ranked contender in the 168-pound division. London’s Ryder, 34, is ranked second by the WBO.

The winner will presumably become the WBO’s mandatory challenger for one of Canelo Alvarez’s four super middleweight championships. Eddie Hearn, Ryder’s promoter, has repeatedly mentioned Ryder as a potential opponent for Alvarez since Ryder upset former IBF/WBA middleweight champion Daniel Jacobs (37-4, 30 KOs) by split decision in their 12-round bout February 12 at Alexandra Palace in London.

Parker was supposed to fight former WBO middleweight champ Demetrius Andrade (31-0, 19 KOs) for the WBO interim super middleweight title May 21 at Pride Park in Derby, England.

Andrade, who moved up from the middleweight division to oppose Parker, withdrew from that fight due to a shoulder injury. Providence’s Andrade declined to participate in a rescheduled bout with Parker following a second straight purse bid that Frank Warren’s Queensberry Promotions won September 22, though thanks to a significantly lower offer than its initial winning bid.

The delays have caused a one-year layoff for Parker, who hasn’t fought since he stopped fellow Brit Marcus Morrison (25-6, 16 KOs) by fourth-round technical knockout last November 6 at Utilita Arena in Birmingham, England. Ryder last fought when he beat Jacobs nine months ago.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.