One man stands in the way of Roger Federer reclaiming the world No.1 throne, and that man is Nick Kyrgios.
The divisive Aussie tennis star has shrugged off the elbow injury that forced him to pull out of the French Open to reach the semi-final of Stuttgart Open (Mercedes Cup), but will now face the ultimate test when he takes on the Swiss Maestro on his favourite surface.
The Aussie was meant to take on fellow countryman Bernard Tomic in the first round of the French Open before he withdrew due to an injury he has been struggling with all season.
Kyrgios came into the tournament as the fourth seed and received a first-round bye. He then defeated world No. 50 Maximilian Marterer in his return to the court after months out through injury, before defeating Spain's Feliciano Lopez in three sets to set up the match with Federer.
MORE: Roger Federer edges closer to world number one after Guido Pella victory
The Fed Express bested Mischa Zverev and Guido Pella to reach the semi final, where he will attempt to take back the men's top ranking of long-time rival Rafael Nadal.
"Funny enough, I didn't think of it," Federer said of the number one ranking after his win over Pella.
"I was really just focused on the task at hand. But I'm sure that the next match, especially now that you reminded me as well, I will think of it. It's all good. In the match that you play for world number one, it's clearly going to be in the back of your head.
"I thought I was in good control. I thought I served well. I didn't give Guido many chances to get into my service games, except maybe the last couple. I was happy that I also got more rhythm."
Kyrgios is seeking his first title on grass, with his only four tournament victories all coming on hard surfaces.
The 23-year-old is in rare form, and if he can continue to produce shots like below then he may have a chance of beating arguably the greatest male tennis player of all time.
Never. Gets. Old.@NickKyrgios 🎉#MercedesCup pic.twitter.com/GZAEGhLxEM
— Tennis TV (@TennisTV) June 14, 2018
"Federer is alright,” Kyrgios said ahead of the match with Roger.
“I’m not gonna sit here and say all those good things about him.
“We already know he's unbelievable, he's the greatest of all-time.
“I’m going to come out tomorrow and have some fun and see how it goes."
The duo have met twice previously, with each player taking the chocolates once.
Federer bested the Aussie in Miami last year after Kyrgios claimed perhaps the biggest win of his career against Federer at the Madrid Open in 2015.
This mouth-watering clash will be played on Sunday at 12:00 AM and can be seen on Fox Sports channel 505, with the winner facing either Milos Raonic or Lucas Pouille in the final.
