Nick Kyrgios reached his first Grand Slam semi-final at Wimbledon on Wednesday when the controversial Australian defeated Cristian Garin of Chile in straight sets.

The world number 40 raced to a 6-4, 6-3, 7-6 (7/5) win and will tackle either Rafael Nadal or Taylor Fritz for a place in the final.

"I never thought I'd be in the semi-final of a Grand Slam. I thought that ship had sailed, that I may have wasted that little window in my career," said Kyrgios.

"I am really happy I was able to come out here with my team and able to put on a performance."

He added: "I felt I was playing on the back foot a lot. Garin's a hell of a player. I got lucky on a couple of break points so I'll take that and will prepare for my next match."

Kyrgios, who shot to fame when he defeated Nadal at the tournament as a 144th-ranked wild card eight years ago, is the first Australian man into the semis at Wimbledon since Lleyton Hewitt in 2005.

He went into the match under a new cloud of controversy after it emerged he faces an Australian court next month to answer an allegation of assault.

His 2022 Wimbledon has also been a rollercoaster.

Brilliant, crowd-pleasing shot-making has been accompanied by $14,000 in fines and an ugly, bitter spat with third-round rival Stefanos Tsitsipas.

The 27-year-old was certainly distracted in the opening stages of Wednesday's match as Garin claimed the first nine points.

But the Australian was back on level terms at 3-3 and grabbed the opening set in the 10th game.

Kyrgios romped through the second set, wrapping it up with his 10th ace of the contest.

Garin, bidding to be the first Chilean to reach a Wimbledon semi-final, ran into a Kyrgios brick wall as the Australian saved eight of the nine break points he faced over the course of the match.

Victory took Kyrgios's grass-court record in 2022 to 12 wins in 14 matches.

"I don't have a coach -- I would never put that burden on someone," said Kyrgios.

"Each and every one of my team plays a very important role. No one knows my tennis more than I do, I've been playing this sport since I was seven and I'm very happy." (AFP)