Pegula has won all her matches in straight sets, including a 54-minute win over Ann Li
Krejcikova saved eight match points to defeat Taylor Townsend in a fourth-round thriller
Krejcikova leads 2-1 in the head-to-head, including a win at WTA Finals 2024
Pegula reached the final last year; this is her third US Open quarter-final
The winner will meet Sabalenka or Vondrousova in the semi-final