Open wildcard a real Bolt from the blue

Three years after giving up tennis in disillusionment, Bolt says he's living the dream after booking a show-court showdown with the world No.4.

"I've always known that I can play at this level," Bolt said after saving four match points in a pulsating five-set win over French former world No.6 Gilles Simon.

"I'm extremely proud of myself. It's been an unbelievable week so far. Hopefully I can keep the roll, keep it going."

Life wasn't so rosy for the big-hitting left-hander when he took up labouring, began building fences and returned to local football in Murray Bridge, South Australia after losing the love of competing.

"I was battling. The competitive side of things on the match court, I just wasn't enjoying myself playing tennis," Bolt said of his nine-month sabbatical in 2016.

"I sat down with my coach a few times. We talked about it. We both decided it was just best to take some time away from the sport because I wasn't enjoying it. There was really no point going through all that."

Bolt made his comeback during the 2017 Australian summer and beat fellow South Australian Thanasi Kokkinakis to qualify for Wimbledon last year in a sign of his promise.

"The big thing was I didn't want any regrets when I was older. I didn't want to say in 10 years, I could have done this in tennis, I could have done that," he said.

"Obviously going back and working as a fencer, you get a little bit of perspective. I guess tennis is a pretty cool lifestyle if you're able to do it.

"I feel like I've chosen the right path to come back and play tennis.

"I enjoy playing tennis a lot more. I don't live and die by winning and losing any more. I'm just out on court trying to have as much fun as I can."

If he can somehow conjure a win over Zverev on Saturday, Bolt will face either Canadian world No.17 Milos Raonic or unseeded Frenchman Pierre Hugues-Herbert for an improbable quarter-final berth.

Australian Associated Press