Lleyton Hewitt's Hopman Cup farewell got off to a losing start as he was beaten 6-3 6-7 (1-7) 6-4 by Jiri Vesely in Group A.
Vesely was unable to hold serve in the third set, but broke the 34-year-old, who is set to retire after the Australia Open, with a passing shot to give Czech Republic a 1-0 lead over Australia Gold.
Karolina Pliskova improved the European nation's advantage with a 7-5 6-3 victory over Jarmila Wolfe.
The Czech duo were then 6-2 7-5 winners in the mixed doubles to claim a 3-0 triumph against Australia Gold.
In Group B, Nick Kyrgios had to come from behind in order to begin his campaign with a 4-6 6-1 6-4 success in his match with Alexander Zverev.
The German teenager edged the opening set, but Kyrgios responded in a strong manner, closing out the match in one hour 23 minutes in Perth.
His victory added to Daria Gavrilova's 6-2 6-2 win over Sabine Lasicki, while the Australia Green pair were 6-3 4-6 10-7 winners in the mixed doubles to complete a clean sweep on the opening day.