Carlos Espi marked his Real Madrid debut with a stoppage time winner, breaking Espanyol hearts as Jose Mourinho's side began the new La Liga season with a dramatic 2-1 victory at the RCDE Stadium on Saturday.
Real Madrid made the ideal start, taking the lead in the tenth minute through Jude Bellingham.
Arda Guler whipped an out swinging free kick into the box from a wide angle, and Bellingham rose above the Espanyol defence to power a header past Joan Dmitrovic.
Espanyol grew into the contest as the half wore on. Alex Calatrava fired into the side netting from a tight angle in the 22nd minute, before German defender Riedel forced a smart save out of Thibaut Courtois with a rasping half volley from distance moments later.
The equaliser arrived in the 30th minute. Espanyol worked the ball down the right before switching play to the left, where Hernandez picked out an unmarked Calatrava inside the box, and the forward swept a first time finish past Courtois to make it 1-1.
Roberto Fernandez almost snatched the lead for the hosts right on the stroke of half time, heading a dangerous cross back into the ground and agonisingly wide of the far post.
Both sides went in level, with Mourinho watching his first competitive game back in charge after 13 years away.
Real Madrid re-asserted themselves after the break. Bellingham headed against the bar from another set piece early in the second half, and Kylian Mbappe somehow put the rebound wide from close range with the goal gaping.
Vinicius Junior appealed for a penalty after appearing to be pushed inside the box, but the referee waved play on.
Riedel was booked shortly after for felling Mbappe on the edge of the area, though the resulting free kick from Mbappe sailed well over the bar.
Mourinho turned to his bench on the hour, sending on Marc Cucurella and Yan Diomande for their Real Madrid debuts in place of Alvaro Carreras and Guler.
Federico Valverde then struck the post from the edge of the box, with Espanyol grateful to escape.
Espanyol continued to threaten on the counter, and Fabio Silva's introduction had not yet been made at that stage of the original account of the reserves, but the closing stages instead turned decisively in Real Madrid's favour after further changes from Mourinho.
Bellingham was forced off late on after rolling his ankle on the turf, replaced by Eduardo Camavinga, with Trent Alexander-Arnold and new signing Espi also introduced in a triple change alongside Bernardo Silva and Denzel Dumfries making way.
The winner arrived deep into stoppage time. Diomande found Mbappe inside the box, and as the forward tried to jink past his marker, goalkeeper Dmitrovic rushed off his line to close him down, only for Espi to nip in and take the ball off Mbappe's toes before slotting into the empty net.
It was a memorable moment for the 20 year old on his first appearance for the club, and it proved enough to seal all three points. Real Madrid held on through four added minutes to complete a 2-1 win and hand Mourinho a winning return to La Liga management.