In 2005, Stosur won her first grand slam title of any sort when she and her doubles partner Lisa Raymond defeated Elena Dementieva and Flavia Pennetta in three sets, 6--2,5--7,6--3 in the final of the US Open.
In 2005, Stosur won her first grand slam title of any sort in the final of Australian Open in the category mixed doubles. In the same year, she won first women's doubles grand slam title with her doubles partner Lisa Raymond defeated Elena Dementieva and Flavia Pennetta in three sets, 6--2,5--7,6--3 in the final of the US Open.