Andy Murray and Heather Watson suffered mixed doubles defeat as Great Britain lost 2-1 to Poland in the Hopman Cup.
Watson, 22, lost the opening rubber 6-3 6-1 to Agnieszka Radwanska, but Murray, 27, levelled the tie with a 6-2 6-4 win over Jerzy Janowicz in Perth.
But the British duo lost the mixed doubles 6-4 6-4 as Group B leaders Poland remained undefeated.
Britain will play Australia on Friday, with only the group winners reaching Saturday's final.
Poland, who are the only team in the group not to lose, will qualify for the final if they beat France on Friday.
The format guarantees all the players at least three singles matches as they prepare for the Australian Open, which begins in Melbourne on 19 January.
|Hopman Cup - Group A|
|Canada: Eugenie Bouchard, Vasek Pospisil||Czech Republic: Lucie Safarova, Adam Pavlasek|
|Italy: Flavia Pennetta, Fabio Fognini||United States: Serena Williams, John Isner|
|Hopman Cup - Group B|
|Australia: Casey Dellacqua, Matt Ebden||France: Alize Cornet, Benoit Paire|
|Great Britain: Heather Watson, Andy Murray||Poland: Agnieszka Radwanska, Jerzy Janowicz|