Britain's Neal Skupski and partner Wesley Koolhof were stunned by wildcards Rinky Hijikata and Jason Kubler in the Australian Open men's doubles quarter-finals.
They had been hoping to reach back-to-back Grand Slam finals after finishing as runners-up at the 2022 US Open.
Hijikata and Kubler are playing their first tournament as a partnership.
They will take on eighth seeds Marcel Granollers of Spain and Horacio Zeballos of Argentina in the last four.
But Skupski's Australian Open is not over as he plays in the mixed doubles semi-finals later on Wednesday, when he and American Desirae Krawczyk face Indian pair Sania Mirza and Rohan Bopanna.