Similar to her success at Wimbledon, Navarro overcame Gauff to reach the US Open final eight.
The world number three overcame a set and a break down to force a decisive set, but the defending champion was badly damaged by numerous double faults.
On Tuesday, the 13th seed will take on Paula Badosa in the round of eight.
Navarro made it clear what her intentions were early on in the encounter as she scored four break points in the second game.
As the 13th seed soaked up the pressure from the defending champion, she frustrated Gauff with her defensive prowess.
But the third seed bounced back nicely, delivering some huge first serves and holding for a 1-1 lead.
Gauff made every effort to sabotage Navarro’s diversity and defensive prowess, but the 13th seed persisted in rerouting everything with greater depth and potency.
After surviving a break opportunity in the third game, Navarro’s steady and relentless return pressure paid off as she converted her fifth break point of the set to take a 4-2 lead.
In an attempt to hurry Gauff’s baseline game and take the forehand early, the 13th seed dared to threaten the double break.
By saving set point to make Navarro serve for the set, the defending champion successfully controlled the pace of the match.
Without wasting any time, Navarro finished the set and continued to undermine Gauff’s strength in the following one.
Navarro dismantled Gauff’s strength by preventing him from using angles and forcing him to work for every point.
Navarro put up another masterclass in early ball-striking, breaking for a 4-3 lead while the reigning champion was under pressure.
With Navarro’s assistance, Gauff managed to find a way to salvage her championship defense, as she had only managed one break point during the entire match.
Gauff regained the lead after Navarro committed a double fault, and the reigning champion didn’t stop there.
Now it was Gauff’s chance to make her opponent make mistakes as she used problem-solving techniques to get back into this match.
Arthur Ashe Stadium erupted in celebration as the match proceeded to a final set after yet another break in the ninth game sealed the second set.
Gauff had the edge of momentum and applied pressure to Navarro, the reigning champion.
Navarro, though, did not let that stop her from holding for a 1-1 lead and playing a calm return game in the next game.
Gauff’s nervousness about serving returned all of a sudden, and even though he managed to save some break opportunities, a double fault gave Navarro the vital break and a 2-1 lead.
Gauff was beginning to lose hope as the double faults kept coming at Arthur Ashe Stadium.
Even though Navarro wasn’t playing her best tennis, she maintained her composure and easily won service games.
Emma Navarro advanced to the quarterfinals with a commanding victory that included another break of serve in the ninth game.
Gauff was disappointed with how her title defense ended, as it was devastating.
Next up for Navarro is a matchup with Paula Badosa in the semifinals.
