Cameron Norrie beat Taylor Fritz in three sets to bring Great Britain level at 1-1 in their United Cup play-off against the United States.
British number one Norrie won 6-4 5-7 6-4 in the Sydney City Final, after team-mate Katie Swan had earlier lost 2-6 6-3 6-4 to American Madison Keys.
Harriet Dart faces world number three Jessica Pegula in the next singles tie.
It is one of three City Finals taking place across Australia, which act as a play-off for the semi-finals.
The winners of the Sydney, Perth and Brisbane City Finals will progress, as will the runners-up with the best record.
GB – captained by Tim Henman – are the surprise package at the inaugural mixed team United Cup, having upset Australia and Rafael Nadal’s Spain in the group stage.
Elsewhere, Jack Draper is out of the Adelaide International after being beaten in straight sets by Karen Khachanov.
The eighth seed won 6-4 6-2 and will play third seed and fellow Russian Daniil Medvedev in the quarter-finals.
