The seventh-seeded Kerber, who had never gone beyond the fourth round at Melbourne Park before, blasted past the dangerous Azarenka 6-3, 7-5 in her first win against the Belarusian.
It was a huge upset for the German, whose six defeats against the 14th seed included this month’s Brisbane International final and an epic three-hour marathon at last year’s US Open.
Her reward is a clash with Konta, whose fairytale main-draw debut tournament continued when she outclassed giant-killing Chinese qualifier Zhang Shuai 6-4, 6-1.
This time last year Konta was ranked 147 and fell in qualifying for Melbourne Park, but she has since risen 100 places, crediting her transformation with a new mental attitude.
“I will just be trying to focus on doing the same stuff I’m doing before every match, focusing on my game,” Kerber said, looking ahead to the semi-final on Thursday.
“I’ll be going out there to win the match, to be aggressive, take my first chances I can get.”
The 28-year-old is a renowned fighter and the quality shone through as she battled back from 2-5 down in the second set against Azarenka, a player who has been in ominous form this season.
Azarenka had lost just 11 games in her four matches prior to meeting Kerber and was seen as the main threat to Serena Williams’ relentless march to a 22nd Grand Slam crown.
World number one Williams plays fourth seed Agnieszka Radwanska in the other semi-final.
“I can’t describe it. I was 0-6 (in their head to head) before I came on court. I said ‘Just go for it and beat her’. I’m so happy to beat her for the first time,” Kerber said.
“It’s amazing to be in the semi-final”