Andy Murray lost to Nick Kyrgios for the first time as he suffered a straight-set defeat in the Hopman Cup.
Australia's Kyrgios won 6-4 7-6 (7-5) in the team event, where Britain's Murray is partnering Heather Watson.
Watson then beat Daria Gavrilova 6-7 (2-7) 6-2 7-5 in a thrilling match to set up a deciding mixed doubles rubber.
Both teams won their opening ties in the round-robin event in Perth, which is a warm-up for the Australian Open in Melbourne, starting on 18 January.
Murray fails to take set point
World number two Murray, 28, won his first four encounters against the 20-year-old, including victories at the Australian, French and US Opens last year.