Australian Open 2020: Alexander Zverev breaks Grand Slam semi-final duck with comeback win in Melbourne (VIDEO)
Zverev had a disastrous opening to the match as Wawrinka raced into a one-set lead after taking the opening set 6-1. But Zverev bounced back superbly and went on to claim the next three sets to take the victory 1-6, 6-3, 6-4, 6-2 at Rod Laver Arena.
"It feels awesome, I don't know what to say," Zverev said after his victory.
"I have done well in other tournaments, I have won Masters, I have won the World Tour Finals but I never could break that barrier in the Grand Slams.
"You cannot imagine what this means to me and I hope this will be the first of many."
After a wobbly start, Zverev found his groove with his serve, and slammed down 13 aces during the matchup as he enjoyed an 80% success rate on his first serve.
It was a noticeable improvement from his serving displays at the ATP Cup, where he suffered a host of issues with his game, including serving a staggering 31 double-faults during the tournament.
But there were no such issues this time around, and he was happy to be asked about his improved serve after the match.
"Thanks for reminding me. I thought I had forgotten about it!" Zverev joked.
"I worked very hard, I worked a lot on it. This is a Grand Slam. This is where you are supposed to play your best tennis and I am doing that."
Zverev also admitted that he was already planning his defeat speech after a disastrous opening set. But he managed to pull himself together and produce one of the most impressive displays of the tournament so far to break Wawrinka's serve five times en route to the final four.
"I was getting ready to talk to the press about why I lost in straight sets to be honest," Zverev laughed.
"Then kind of turned it around and my energy picked up a little bit."
Zverev will face either Rafael Nadal or Dominic Theim for a place in Sunday's final. And if the German goes on to win the tournament, he said he will pledge all $2.82 million of the prize money to the Australian bushfire relief fund.Also on rt.com Marijana Veljovic: Meet the 'super pretty' tennis umpire setting pulses racing at the Australian Open