Jessica Pegula is one of the players who, depending on results, could take over as world number one after the US Open. However, the world number three had major problems at the start of the quarter-finals.
27th-ranked Navarro upset Pegula and after five double faults the 32-year-old smashed her racket to the ground in frustration.
But in the next two sets, it was Pegula's match, and she advanced to the semifinals after 3-6, 6-4, 6-3.
The match between the Americans was dubbed the "billionaires' fight" in advance, as both Pegula's and Navarro's fathers are successful businessmen.
In the semifinals, world number one Aryna Sabalenka awaits. However, Pegula can take over the top spot - if she wins the entire US Open and world number two Jelena Rybakina loses in the quarter-finals.
