Payne complained of abdominal pains after she fell from Dutch Courage, trained by her brother Patrick.
But doctors established that the 30-year-old had avoided serious damage.
And Payne tweeted her thanks to fans for "well wishes" and revealed she is due for tests on her liver and pancreas.
The tweet included a picture of her bruised abdomen and revealed she will be transferred to the Alfred Hospital in Melbourne for further tests.
State regulator Racing Victoria tweeted: "Scans have cleared Michelle Payne of serious injury. She will stay for observation overnight."
Payne created history last November when she became the first female jockey to win the Melbourne Cup - Australia's most prestigious horse race - aboard Prince Of Penzance.
Earlier this month she stated her intention to ride in Europe this summer and has been pencilled in to feature at Royal Ascot in June.
Melbourne Cup-winning jockey Michelle Payne escaped serious injury from a fall at Mildura in Australia but will remain in hospital overnight.