US Open champion Alfie Hewett was one of three Britons to suffer defeat as the wheelchair tennis competitions got under way at the Australian Open.
Hewett, 21, was outplayed in the 6-1 6-4 loss to world number one Shingo Kunieda of Japan.
Lucy Shuker, a 2017 semi-finalist, was overwhelmed 6-0 6-0 by Dutch top seed Diede de Groot in the women's singles.
And Andy Lapthorne lost 6-1 4-6 6-4 to number two seed David Wagner of the USA in the men's quad event.
Scot Gordon Reid, the 2016 champion, faces Frenchman Stephane Houdet in his opening match.