Reigning Newcombe medallist Dylan Alcott has beaten close mate and Paralympic teammate Heath Davidson in the first round of the Australian Open quad wheelchair draw.
The pair combined to bring home Australia's first quad wheelchair Paralympic gold medal in Rio last year.
But friendships were put to one side at Melbourne Park on Wednesday as top seed Alcott recorded an impressive 6-1 6-4 win over the wildcard.
Alcott, a two-time champion at Melbourne Park, is out to defend the title he won last year.
Davidson can still recover to make the final, however, with the quad wheelchair draw using a round robin format to decide the two finalists.
In the other quad wheelchair match played on Wednesday, Brit Andy Lapthorne overcame No.2 seeded American David Wagner 6-3 6-3.
In men's wheelchair quarter-finals action, local wildcard Ben Weekes was beaten by Argentina's Gustavo Fernandez in straight sets.
British top seed Gordon Reid was upset by unseeded Belgian Joachim Gerard in three sets, while French second seed Stephane Houdet progressed in three sets over Brit Alfie Hewett.
France's Nicolas Peifer and defeated Maikel Scheffers of the Netherlands 6-2 6-3.
In the women's draw, Dutch No.1 seed Jiske Griffioen and second seed Yui Kamiji of Japan both advanced to the semi-finals in straight sets.
German Sabine Ellerbrock defeated the Netherlands' Diede De Groot 6-4 6-3 and Brit Lucy Shuker overcame Marjolein Buis 6-2 6-3.
