The Cuscatlecos were held to a draw after the Ticos drew level through Randall Brenes, who scored deep in injury time
El Salvador had a surprise lead erased at the death as Costa Rica came back from the brink of defeat to earn a draw in Thursday's Gold Cup match.
The Cuscatlecos entered the half-time break with a lead thanks to Rodolfo Zelaya's stunning free-kick, converted just moments before the interval. The 22-year old's strike shocked the Ticos, who had looked dangerous, with Alvaro Saborio having multiple good chances fail to find their way into the net.
Following the half-time interval, Costa Rica controlled the majority of possession and were rewarded for their efforts deep into injury time. Randall Brenes, a late substitute, made his impact in the 95th minute when he scored the equaliser.
The result sees Costa Rica move one point clear of Mexico for the lead in Group A at the moment. El Salvador would have entered a three-way tie for first place with a win, but instead move third.