By SABC Sport
13th August 2023
Swiatek, who has topped the women's rankings for 72 weeks, lost out to world number three Pegula 6-2 6-7(4) 6-4 after two-and-a-half hours.
Poland's Swiatek had led 4-2 in the final set after fighting back from the brink before her American opponent won the last four games.
Pegula had served for the match at 5-4 up in the second set and had led 4-2 in the tie-break before Swiatek hit back to force a deciding set, but it was too little too late.
"It was a great match," reflected Pegula.
"It was tough. Kind of a roller coaster. Really up and down, but I'm glad I was able to hold my nerve there at the end."
The 29-year-old will play the winner of Elena Rybakina and Liudmila Samsonov's semi-final which has been postponed to Sunday due to rain in Montreal. The final will then be held later on Sunday evening after the winner of the semi-final has a suitable time to rest.
Meanwhile, Swiatek admitted to being tested by Pegula and vowed to rewatch the match to analyse what went wrong.
"She really pushed me, so I needed to change something up," said the Pole.
"It was working, but in the third, I don't really know what happened when I was leading. I've got to watch the match and analyse it, because for sure she was fighting for every point and I did as well. It was a tricky match."