John Ryder stood at the gate long enough to push his way through.

A battle of top-rated British super middleweights saw Ryder claim a long-elusive big win at the contender level, as he claimed a fifth-round injury stoppage over Zach Parker. A competitive fight was brought to a sudden halt at 0:01 of round five, when it was learned that Parker suffered a broken right hand and could not continue in their BT Sport/ESPN+ aired main event Saturday at The O2 in London.

Ryder claims the interim WBO super middleweight title with the win, and positions himself as the WBO mandatory challenger to undisputed super middleweight champion Saul ‘Canelo’ Alvarez (58-2-2, 39KOs).

“I thought the tide was starting to turn and I was getting more on top,” Ryder said after the win. “These things happen in boxing. It was a bad injury for him but it feels like a robbery of a victory for me. It’s just one of those things.”

Parker used his height and reach to keep Ryder at the end of his punches in a competitive opening round. Ryder used feints to set up his left hand, though Parker was prepared for the tactic. The unbeaten super middleweight contender from Derbyshire stunted the 35-year-old Londoner’s attack by constantly switching between and orthodox and southpaw.

Ryder sought to impose his will in round two. He briefly paid the price, as he was caught by Parker. Action remained at a moderate pace, which Ryder attempted to exploit with his mauling style. Parker successfully spun his way out of a clinch and then responded with a straight left hand from long range out of the southpaw stance.

Neither fighter found much of an offensive rhythm in round three. Parker landed a pair of power shots late in the frame, neither of which caused much damage although Ryder was forced on the defensive. Ryder managed a stiff right jab at the bell but left without time to properly follow up on the sequence.

Parker found success with singular shots early in round four. However, it was the shot he didn’t land—a right uppercut picked off by Ryder’s gloves—that proved to be the most damaging blow.

“I’m obviously gutted,” said a dejected Parker. “It was a fucking uppercut at the start of the (fourth) round. You could see how bad it’s hurt now. I’m gutted but I hope he goes on to good things. I’ll obviously come back stronger.”

Constant movement by the 28-year-old provided opportunities to land with his lead left hands and double up on his jab. Ryder was eventually able to time his mobile foe, cutting off the ring and landing a straight left hand. Time was called to reinsert Parker’s dislodged mouthpiece, though Ryder managed another left hand before the bell.

It was the last punch thrown in the fight.

The bell sounded to begin round five, at which point it was learned that Parker was done for the night. Ryder felt the momentum was riding in his favor, only to learn of Parker’s demise.

Parker fell to 22-1 (16KOs) with the defeat, adding to a bitter 2022 campaign that saw two separate failed attempts at securing a fight with Demetrius Andrade. Both fight attempts—including the canceled May 21 event due to an Andrade shoulder injury—would have come with the interim WBO title at stake.

The fallouts resulted in a 55-week ring absence, with Saturday’s defeat also ending a near three-year stay as the number-one ranked WBO super middleweight contender.

“It was warming up into a good fight,” noted Parker, who faced his first career southpaw.

Parker led 39-37 on two scorecards, with the fight scored even at 38-38 even on the third card.

Ryder improved to 32-5 (18KOs) with the win, capping a terrific 2022 campaign. The 35-year-old enjoys a four-fight win streak since a disputed twelve-round, unanimous decision to then-unbeaten WBA super middleweight titlist Callum Smith in November 2019. He entered the year with a twelve-round nod over former IBF middleweight titlist Daniel Jacobs on February 12 in Muswell Hill, London and now leaves The O2 with his biggest domestic win and—should the WBO next enforce his mandatory status—boxing’s equivalent of hitting the jackpot.

Current WBO rules state that Alvarez has until May 18, 2023 to honor his mandatory title defense. The Mexican superstar has seen five of his past six fights presented by Matchroom Boxing, who promotes Ryder.

“I’m standing pretty now,” stated Ryder. “It would be a dream to fight Canelo on Cinco de Mayo… whenever or wherever. It’s a great win for me. This is where I want to be, whether to fight Canelo for any of the four belts, so be it.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox