Seven-year-old Nick Kyrgios. [Photo provided by Australia Plus]

SYDNEY - The world's tennis greats are calling Australian teen sensation Nick Kyrgios the game's new super star after he caused one of the greatest upsets in Wimbledon history by knocking out world No. 1 Rafael Nadal on Tuesday.

Kyrgios, 19, the first player ranked outside the top 100 to defeat a world No.1 since Andrei Olhovskiy stunned Jim Courier in the Wimbledon third round in 1992, is already being compared to the game's greatest-ever players including Pete Sampras and Boris Becker.

Former Wimbledon champion Pat Cash has ranked Kyrgious's explosive performance equal to that of fellow Aussie Mark Philippoussis, who stunned another world No.1, Pete Sampras, in three sets to reach the fourth round of the Australian Open in 1996.

"He (Philippoussis) blew everybody away, and everybody was in shock from that one, said 'a star is born', and he pretty much was, " Cash told the Age newspaper. "And it's the case here as well.

"That's what it reminded me of, where (Kyrgios) just didn't go away - he kept going for the shots and kept coming up with the goods. It was extremely impressive. It was amazing. It was almost faultless."

U.S. tennis legend John McEnroe compared Kyrgios to Boris Becker, who won at Wimbledon in 1985 as a 17-year-old.

"I keep saying 'who's the next guy?' and I think that we've found that guy," said John McEnroe on the BBC. "How did he keep that up?"

Australian doubles champion Todd Woodbridge compared Kyrgios to a young Pete Sampras.

"That was the most extraordinary tennis I've seen from a teenager maybe since the likes of Pete Sampras when he kind-of made his statement on tour," Woodbridge said.