Raphael Collignon defies cramps to secure shock Davis Cup victory over Alex de Minaur

In a stunning upset at Ken Rosewall Arena on Saturday, Belgium's Raphael Collignon secured an unlikely victory over Australia's Alex de Minaur in the opening singles rubber of their Davis Cup tie, battling through a debilitating cramp to claim the win.

The 7-5, 3-6, 6-4 victory, which came despite Collignon suffering severe cramping for much of the match, marks the world No.91's first career win over a top-10-ranked player.

Just weeks after securing the biggest win of his career against world No.12 Caspar Ruud at the US Open to crack the top 100 for the first time, Collignon faced a formidable challenge against the world No.8 in de Minaur.

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The first set was a tense affair, with both players testing each other's resolve.

Despite nervous tension, Collignon broke the first three service games but could not capitalise on his early advantage.

However, he managed to hold his ground, preventing de Minaur from clinching a crucial opening set.

The momentum of the match took a dramatic turn in the second set.

De Minaur surged back, winning 10 consecutive points to take a clinical second set.

Collignon, visibly struggling with severe leg cramping, was on the brink of retirement — even removing his hat and approaching the umpire, seemingly ready to concede the match.

However, with the support of his team and the unique situation of playing for your country, the 23-year-old managed to push through a gruelling 15-minute game.

He was forced to sacrifice a point to receive medical treatment during a game. Collignon also received massage at the change of ends.

With his movement severely limited, Collignon abandoned his usual strategy and resorted to a high-risk approach, free-hitting winners and aggressively coming to the net.

It was a Hail Mary move that paid off spectacularly.

"You have to give [Collignon] so much credit. He didn't have too many options after he started cramping, and all he could do was go for it after the first or second shot, and that's exactly what he did," Jelena Dokic said in commentary for Nine.

"He probably would have retired if he wasn't playing Davis Cup and playing for his country."

Speaking post-match, Collignon expressed his disbelief at the result.

"It feels amazing, I thought I wouldn't be able to finish the match because I got cramp so bad at the beginning of the third," he said.

"I tried to play with that strength, tried to go for it, focus on the serve, and I don't know how I won, yeah, crazy.

"I think when you play for your country, there is no pain … I am very happy I won."

While Collignon will celebrate an extraordinary victory fueled by sheer will, de Minaur will be left to reflect on a difficult loss.

Speaking post-match, Todd Woodbridge believed de Minaur was expecting his opponent to eventually break down, but Collignon's courageous style proved too much to handle.

"He seemed to be absorbing it all in, thinking he would be able to maneuver his way around and that [Collignon] would eventually crumble," he said.

"But that's not what happened, so he'll learn some big lessons."

At the conclusion of day one, Belgium leads the tie 2-0 after Jordan Thompson subsequently lost his singles rubber 7-6, 6-4 to Zizou Bergs.

The doubles rubber and any necessary reserve singles matches will take place on day two, with a place in the Davis Cup finals on the line.

To qualify, Australia must win all three of the remaining rubbers on day two.