Storm Sanders gave Australia a massive boost in Prague with a 3-6, 7-6 (7-5), 6-0 win over Belgium’s Elise Mertens to send the Aussie women into the semi-finals of the Billie Jean King Cup.

Australia need to beat Belarus tomorrow to secure a place in the last four of the event, formerly known as the Fed Cup.

And the Aussies did it without world No.1 Ash Barty and Ajla Tomljanovic, who withdrew on match day with an injury.

Daria Gavrilova upset Greet Minnen 6-4, 1-6, 6-4 to get the ball rolling before Sanders, ranked 131 in the world, stormed past Mertens.

Sanders and Ellen Perez lost the doubles to Mertens and Minnen 6-2,6-4 but the 2-1 victory sealed Australia’s first success over Belgium in the competition since 1984.

“To do it in this moment, representing Australia, it is just the best feeling ever,” Sanders said after her win.