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.