The biggest breakthrough yet has arrived: No. 6 Jessica Pegula is into the first Grand Slam semifinal of her career via a shocking 6-2, 6-4 domination of world No. 1 Iga Swiatek. Pegula had never previously been past the quarterfinals in any slam in her career and hadn't made it past the second round in any major this year.

American Jessica Pegula pulled off a major upset of No. 1 Iga Swiatek at the US Open on Wednesday night to reach her first Grand Slam semifinal.