Giant-killer Kyrgios spurred by Malaysian mum's doubts

The teenager told the Australian Associated Press (AAP) he was surprised to read an interview from Australia in which his mother Norlaila talked down his chances against Nadal in the fourth round.

"Last night, I was reading a comment that she thought Rafa was too good for me," said Kyrgios, after his 7-6 (7-5) 5-7 7-6 (7-5) 6-3 victory on Tuesday. It made me angry," he is quoted as saying.

"I just believed in myself that I could create some opportunities and I took them under pressure," he said.

Kyrgios is from a tight-knit family but his mother and brother Christos, a lawyer, have remained home in Canberra while his father George and sister Halimah, an actress, are at Wimbledon with him.

Asked what he would say to his Kuala Lumpur-born mother after the win, Kyrgios said: "I'll just send her a smiley face."

Halimah sat next to her father in anguish for much of the three-hour battle on centre court.

She said the pair had been quietly confident of Nick's chances against Nadal but, seeing him shine so brightly on the biggest stage, was an emotional experience.

"I just started crying. To be honest, I've never been so shocked and overwhelmed at the same time. He played the best tennis I've ever seen him play" Halimah told AAP.

Halimah wasn't surprised to see her brother lap up the big occasion. "He loves the crowd, I think that's one of the ways that helped him win," she said.

AAP said in the match of his life, on the biggest stage in tennis, against one of the greatest of all time, Nick Kyrgios, delivered a performance for the ages.

Kyrgios, a wildcard entrant ranked 144th, has set up a last-eight showdown on Wednesday with Canadian eighth seed Milos Raonic.

Former winners John McEnroe and Pat Cash believe the fearless Kyrgios can go on to emulate Boris Becker by winning the Wimbledon title as a teenager.

Nadal said defeat was hard to take as he only lost serve once.