Kevin Doyle opened the scoring with a header but Celso Borges levelled from the spot before Robbie Keane failed from 12 yards out
Costa Rica avoided a second straight defeat thanks to Celso Borges' spot-kick cancelled out Kevin Doyle's opener, while Ireland captain Robbie Keane was denied from 12 yards out soon after by substitute goalkeeper Patrick Pemberton.
Pemberton, who replaced Keylor Navas at half-time, was crucial to Costa Rica holding on for a draw at PPL Park, Pennsylvania, with the Central Americans playing the entire second half with 10 players due to Giancarlo Gonzalez's 41st-minute red card.
After Borges equalised and Keane saw his penalty saved, Ireland pushed hard for a winning goal with the latter testing Pemberton at the near post before Shane Long unleashed a shot from outside the box - but Costa Rica's 32-year-old goalkeeper was up to the challenge on both occasions.
Costa Rica entered the friendly with four defeats in their past five fixtures and coach Jorge Luis Pinto made four changes from the starting line-up against Japan.
Yeltsin Tejeda, Cristian Bolanos, Cristian Gamboa and Roy Miller were relegated to the bench, and they were replaced by Marco Urena, Jose Cubero, Heiner Mora and Oscar Duarte.
Ireland manager Martin O'Neill made widespread changes with just Anthony Pilkington remaining from the starting XI that drew with Italy on May 31.
Possession generally remained in the middle third of the pitch for the opening 15 minutes as both sides struggled to break down the opposing defences.
But in the 18th minute, Ireland hit the front with Marc Wilson crossing from deep on the left to Doyle, who powered his header from just inside the penalty area past the outstretched left hand of Costa Rica goalkeeper Navas.
After going ahead, Ireland seemed happy enough sitting deep in defence and attempting to hit Costa Rica on the counterattack through captain Keane.
Faced with a packed defence, Costa Rica struggled to get in behind, while the physicality of the Irish clearly made Pinto's men uncomfortable, who were restricted largely to shooting from long range.
The Concacaf nation's best chance of the first half fell to Borges in the 39th minute after Ireland goalkeeper David Forde failed to punch Mora's cross clear but the Costa Rican midfielder's attempted overhead kick looped just over the bar.
Costa Rica were reduced to 10 men just two minutes later.
Gonzalez was shown a yellow card for an elbow to Doyle's head, which left the Wolves forward bleeding, and the Costa Rican defender's criticism of the referee saw him sent off.
In the shadows of half-time, Duarte also had a chance to equalise for Costa Rica but his back-post header from Borges' free-kick drifted wide.
Costa Rica came out full of intensity after the break with Urena, Joel Campbell and Mora all failing to take their chances, and the nominal hosts needed a spot kick to equalise.
In the 63rd minute, Campbell's fine through ball released Urena and the Krasnodar striker was tripped by Forde, with Borges smashing the spot-kick straight down the middle to make it 1-1.
Just three minutes later, Ireland had a penalty of their own when Mora fouled Stephen Quinn but Keane was unable to beat Pemberton from the spot.
Both sides had chances to win the match after Pemberton's penalty save with Campbell curling a shot wide of Forde's far post before Keane got a toe on James McClean's cross only to be denied again.
In the 78th minute, Long cut in from the left and smashed a shot on target but Pemberton tipped the ball around the post, and the match petered out to end in a stalemate.