Nick Kyrgios' first ATP Tour match since March ended in a straight-set defeat by Aleksandar Kovacevic in the opening round of the Brisbane International.
The 30-year-old Australian, who had played only six ATP singles matches in the past three seasons and was given a wildcard for the event, was beaten 6-3 6-4 in just 65 minutes by American Kovacevic.
The defeat follows Kyrgios' victory in the 'Battle of the Sexes' exhibition match against women's world number one Aryna Sabalenka last month.
As he is now ranked 670th, Kyrgios is aiming to build his fitness so he can gain a wildcard for the Australian Open, which begins on 18 January in Melbourne, after suffering a string of serious injuries in recent years.