Claiming the first break of the match in the eighth game, Navarro saved a break point before serving out the opening set, but Sabalenka fought back to win the second.
After exchanging breaks early in the decider, Navarro struck again for a 3-1 lead as Sabalenka’s serve faltered and, after saving the first match point, the two-time major winner missed the second to hand Navarro the biggest win of her career.
The victory continues a strong season for the 22-year-old, who claimed her first WTA Tour title in January at the Hobart International.
“I’m feeling really good. It’s never easy coming out and playing an opponent like that – so experienced and just so talented,” Navarro said.
“She made it really tough on me today, but I was glad I was able to play some good tennis in the big moments.”
Russian fourth seed Daniil Medvedev claimed a 6-4 6-4 victory over Bulgaria’s Grigor Dimitrov to reach the men’s quarter-finals.
Medvedev will face Danish seventh seed Holger Rune, who saved a match point on his way to a 2-6 7-6 6-3 win over American 12th seed Taylor Fritz.
Indian Wells is the only one of the six hard-court ATP Masters 1,000 tournament that Medvedev has not won.
Norway’s ninth seed Casper Ruud overcame Frenchman Gael Monfils 3-6 7-6 (7-3) 6-4 to reach the last eight.
Ruud will face American Tommy Paul, a 6-4 6-3 winner over Italy’s Luca Nardi, who knocked out world number one Novak Djokovic in the previous round.
