A goal from Inter Milan midfielder Emre Belozoglu looked to have given Turkey all three points until Costa Rica substitute Winston Parks equalised four minutes from time.
Turkey, who lost 2-1 to Brazil in their opening match, now have only one point from two matches.
They need to beat China in their final game and hope Brazil defeat Costa Rica to have a chance of progressing.
Even then goal difference would decide who went through to the second round.
But Gunes said: "We are confident of a win against China and we will wait for the right result to go through.
"We are here at the World Cup after 48 years. We scored our first goal against Brazil and got our first point against Costa Rica."
Yet Gunes admitted he was unhappy to have drawn with Costa Rica.
"It is a bitter disappointment," he said. "We were playing to win but after the goal some of our players got tired and Costa Rica began to play more offensively and made more chances.
"The Costa Rican defensive three were very solid and their team played very aggressively and we couldn't create clear-cut chances."