The young German recovered from a dire start to see off three-time major winner Stan Wawrinka 1-6 6-3 6-4 6-2 in their Australian Open quarter-final on Wednesday.

Touted years ago as tennis's next big thing, Zverev had never previously made it past the fourth round at Melbourne Park.

His only two quarter-final runs at a major both came on clay at Roland Garros.

"You guys can't imagine what this means to me. I hope this will be the first of many," the 22-year-old said.

"It feels awesome. I don't know what to say. I mean, I've done well in other tournaments. I've won matches, but I never could break that barrier in a grand slam."

After suffering from a serious bout of the summer serving yips, Zverev arrived in Melbourne on the back of three straight losses at this month's ATP Cup.

Zverev admitted high expectations may have fuelled his past grand slam flops, but his ATP Cup woes proved a blessing in disguise.

"I was paying too much attention to them (grand slams)," he said.

"This year I actually came into the Australian Open with absolutely no expectations because I was playing horrible."

After battling through his Open opener against Marco Cecchinato, the out-of-sorts world No.7 pledged to donate his entire winner's cheque to the bushfire victims if he won the Open.

And he's standing by it, insisting he will keep his promise.

"Of course, if I win the $4 million, it's a lot of money for me," Zverev said, adding he wasn't brought up to be a money-driven person.

"I'm not Roger (Federer), I'm not LeBron James, (or) something like that. This is still big.

"But at the same time I know that there's people right now in this country, in this beautiful country, that lost their homes and actually they need the money.

"They actually depend on it, building up their homes again ... building up the nature that Australia has, the animals as well.

"There's much better use for those people with that money than I have right now.

He still has a way to go.

Zverev must overcome either world No.1 Rafael Nadal or fifth seed Dominic Thiem in Friday night's semi-final and then Novak Djokovic or Roger Federer in Sunday's championship match.

Australian Associated Press