"I'm gonna ask you some Australian-based questions, and you buzz in if you know the answer. Whoever gets the most right is the best Australian,besides my wife, Portia de Rossi of course," Ellen said to introduce the amusing segment.
They got off to a strong start, with Robbie easily naming an Olivia Newton-John song and Hemsworth remembering the name of the Australian children's show his brother Liam Hemsworth co-starred with Robbie on, "Elephant Princess."
But then it was downhill from there.
Hemsworth couldn't recognize a wax figure of Liam (points went to Robbie for that one), neither knew where fellow Australian actress Nicole Kidman was born, their Crocodile Dundee impressions were awful, and they didn't even know the time difference between California and Australia.
Ellen declared Hemsworth the winner, but only because he was able to answer a question about U.S. current events: "Neighbor is a popular soap opera down under. Which one of my neighbors may run for president in 2020?"
Elsewhere in the show, Robbie shared an embarrassing story of how she first met Ellen, while on her honeymoon in Tahiti with husband Tom Ackerley. Not only did they run into Ellen and Portia de Rossi while Ackerley was wearing the shortest shorts imaginable, but they ended up meeting Barack and Michelle Obama too!
"Ellen looks over and goes, 'Boy, those were the wrong shorts to wear today," Robbie explained. Watch the video below: