After knocking Serena Williams out of the ASB Classic, Madison Brengle was stopped in the quarter finals by Latvia's Jelena Ostapenko.
The Latvian seventh seed beat the American in a first set tie-break before comfortably taking the second 6-3.
In Friday's semi finals, Ostapenko will meet the American, Lauren Davis, who was the first player through to the next round after defeating the fourth seeded Czech, Barbora Strycova, in straight sets.
Also through to the semi-finals is the Croatian eighth seed Ana Konjuh.
The 19-year-old was leading Naomi Osaka 3-0 in the first set of their quarterfinal today when the Japanese player was forced to retire due to injury.
Konjuh will play either the tournament favourite and third seed from Denmark, Caroline Wozniacki or Germany's Julia Görges.