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Pegula led Gauff 7-5 6-6 (3-1) when rain in the German capital halted play, with a later announcement confirming the match will not resume until Sunday.

Both players had already taken to the court once as Gauff's last-eight opponent Ons Jabeur retired with illness after losing a 68-minute opening set 7-6 (11-9).

Pegula, meanwhile, wrapped up a two-day quarter-final victory over Katerina Siniakova by a 7-6 (7-2) 3-6 6-3 scoreline.

The winner of the pair's match will also have to play twice on Sunday, with Kalinskaya lying in wait in the final after she beat former world No.1 Victoria Azarenka 6-1 6-7 (3-7) 6-1.

Whoever emerges victorious, Kalinskaya will face a top-five player, with Gauff currently No.2 in the world rankings and Pegula No.5.

Kalinskaya has already recorded three top-five victories this year.

She lost her only previous meeting with Pegula in Washington D.C. in 2019 but won her first clash with Gauff in Dubai earlier this year.