Britons Andy Murray and Heather Watson registered singles wins on a sweltering day in Perth to help give Great Britain a 3-0 Hopman Cup whitewash of Germany.
On a morning when temperatures rose to 36 degrees, Watson beat Sabine Lisicki 6-3 6-4 before Murray overcame Alexander Zverev 6-3 6-4.
The pair then teamed up for a 6-3 6-4 win in the mixed doubles.
Britain still need France to beat Australia Green in the last group game to reach Saturday's final.
For Watson and Murray, the competition is useful preparation for the Australian Open, which starts in Melbourne on 18 January.