Aston Villa goalkeeper Emi Martinez was the hero as Argentina booked their spot in the Copa America semi-finals with a 4-2 penalty shootout win over Ecuador.
After a 1-1 draw in normal time, the match went straight to penalties and Argentina got off to the worst possible start when captain Lionel Messi saw his chipped effort hit the crossbar.
But Ecuador failed to take advantage, Martinez saving their first two spot kicks from Angel Mena and Alan Minda.
Manchester City's Julian Alvarez and Liverpool's Alexis Mac Allister scored for Argentina, while former Manchester City defender Nicolas Otamendi stepped up to convert the winning penalty after John Yeboah had kept Ecuador's hopes alive.
The underdogs had forced penalties with an injury-time equaliser, Kevin Rodriguez heading an in-swinging cross past Martinez
Manchester United defender Lisandro Martinez had given Argentina the lead in the first half when he headed home from close range following a corner.
The World Cup holders were far from their best in Houston and Ecuador missed a chance to level on the hour-mark when captain Enner Valencia hit the post from the penalty spot after Rodrigo De Paul was penalised for handball.
Martinez, who taunted the Ecuador fans following his spot-kick saves in the shootout, turned to a largely-Argentine crowd in Houston following Valencia's miss and pumped his arms in their direction.
The former Arsenal goalkeeper has now faced 24 penalties for Argentina and has conceded just 12 with nine saves and three off-target misses.
Argentina, the 15-time winners of the Copa America, will face either Canada or Venezuela in the semi-finals.
Ecuador parted ways with manager Felix Sanchez after the defeat, despite the Spaniard having three years to run on his deal.
"We thank Felix and his coaching staff for their work and professionalism, and wish him success in his future endeavours," the Ecuadorian Football Federation said in a statement.
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