Gekas spent three months with Spanish side Levante in 2012, and Navas has said that he remembered where the striker aims his spot kicks from their days on the training ground.
"We played together at Levante and I remembered what he used to do in training," Navas told FIFA.com.
"I was confident he wasn't going to change the way he takes his penalties and in the end I was able to keep it out.
"My teammates also deserve praise for putting all their penalties away. I took confidence from that and it definitely helped me."
Costa Rica will play the Netherlands in the last eight on Saturday.