Purcell and Saville came back from a set down to defeat fourth seeded Ivan Dodig and Filip Polasek 6-7(7) 6-3 6-4 in two hours and 20 minutes.
The pair were granted wildcard entries to this year's event, and have been on a hot streak after defeating eighth seeds and 2017 US Open champions Horia Tecau and Jean-Julien Rojer in the second round.
They will look to bring home their first Grand Slam title when they face the formidable pairing of Rajeev Ram and Joe Salisbury, who defeated Alexander Bublik and Mikhail Kukushkin 4-6 6-3 6-4 in an hour and 49 minutes.
Having won titles in Dubai and Vienna last year, Ram and Salisbury are the more accomplished duo. However, the wildcard team of Max Purcell and Saville will have the full support of the Aussie crowd when they clash this weekend. Their Cinderella story may not be over yet.
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