Petr Cech had been a wall and guarded the goal for the Czechs successfully for 86 minutes, but then defender Gerard Pique used his head to rescue Spain in their Euro 2016 opener and beat the resolute goalkeeper.
The Barcelona defender struck a late winner as the defending champions opened their Euro 2016 campaign with a 1-0 victory over the Czech Republic.
Pique headed a late winner with three minutes left on the clock in Spain's Group D opener in Toulouse on Monday.
Spain's defender Gerard Pique (R) scores a goal past Czech Republic's goalkeeper Petr Cech (L) during the Euro 2016 group D football match between Spain and Czech Republic at the Stadium Municipal in Toulouse on Monday. Pic/AFP
Spain, 2008 and 2012 European champions, may have been dominant throughout the game, but unable to break down the Czechs and looked like they would be drawing a blank until Pique struck.
Spain's build-up to the tournament wasn't as smooth as they would have liked with a sex scandal involving goalkeeper De Gea raring its ugly head last week.
Coach Vicente del Bosque though showed his faith in the Manchester United shot-stopper by handing him the gloves ahead of legendary Iker Casillas.
The Czechs have to thank Arsenal 'keeper Cech for not losing by a bigger number.
Spain were repeatedly frustrated by the Czechs' stubborn defense, which finally fell apart when Pique got his head to Iniesta's brilliant cross towards the back post in the 87th minute.
Roman Hubnik almost scored an own goal while Alvaro Morata and Jordi Alba were denied by Cech at the Stadium Municipal.
Spain spent most of the game camped inside the Czech half and are now level with Croatia after their 1-0 win over Turkey on Sunday.
Spain were on the attack from the go and in the 16th minute fashioned their first real chance with right-back Juanfran sending David Silva through on the right flank for the Manchester City man to fire in a perfect delivery for Morata. Cech, however, was well positioned to block the Juventus striker's first-timer from close range.
The Czechs were defending with plenty of heart and only a desperate sliding tackle from centre-back Tomas Sivok stopped Juanfran's short delivery reaching Morata as the Spaniards edged closer.
When Iniesta picked up a mis-hit clearance just outside the area to set up Morata, the Juventus striker feinted before flashing a low drive wide of Cech's far post on the half hour.
Iniesta recovered from a knock on the ankle and, with Cech off his line, sent an audacious chip from 35 yards metres wide of the post. Cech was forced into action twice before the interval, the 'keeper diving to parry Jordi Alba's angled shot from the left side of the area then rushing out to block at the feet of Silva as he prepared to pull the trigger after being set up by Juanfran.
A counter-attack involving Czech captain Tomas Rosicky gave Tomas Necid the chance to test De Gea from the edge of the area but the 'keeper saved comfortably.
Cech came under more intense pressure in another one-sided half after the restart, the 'keeper desperately turning the deflection from a Morata pass around the post before blocking Ramos's effort from inside the area from the resulting corner.
After Athletic Bilbao striker Aritz Aduriz came on to replace the misfiring Morata, De Gea had Cesc Fabregas to thank when he produced a spectacular overhead kick to keep Theodor Gebre Selassi's header out following a corner.
Fabregas was replaced by Thiago Alcantara soon after, and Spain's pressure intensified but to no avail till Pique headed one in.