Real Madrid escaped the trap set by hosts Elche in the dying moments, though the manner of it will worry their fans ahead of next Sunday's eagerly awaited derby against Atletico Madrid.
They looked to be cruising to an easy win. Then they made life hard for themselves before snatching three points against the odds, edging a 3-2 win on Tuesday evening at the Manuel Martinez Valero in the sixth round of the Spanish league.
The victory lifted Real Madrid to second on 15 points, level with leaders Barcelona but behind on goal difference. Barca can stretch the gap if they beat Racing Santander on Wednesday.
Five wins this season now stand against a single defeat, that away loss to Real Betis in the fourth round.
Elche, meanwhile, remain frozen on just two points at the bottom.
The suffering continues away from home
Even in victory, Real Madrid's away struggles rumbled on.
Across their last nine La Liga matches on the road before Elche, they stumbled five times, losing four, the most recent against Real Betis, and drawing once. Today they narrowly avoided a fifth defeat.
What makes it worse is where they head next. Real Madrid travel to face their capital neighbours at the Metropolitano, another test away from the Santiago Bernabeu, and today's second-half slump only sharpens the concern.
Mourinho's gamble
Jose Mourinho rang the changes from the previous match. Most eye-catching was dropping Jude Bellingham to hand Arda Guler a start, restoring Aurelien Tchouameni in midfield after a long absence at the expense of Bernardo Silva, and resting Denzel Dumfries, the usual right-back.
That was only the start. Once his side led in the second half, Mourinho pulled off Vinicius Junior and Arda Guler with the derby in mind.
The gamble almost backfired. He found himself pegged back to 2-2 in the closing minutes before substitute Carlos Espi rescued him.
Resting a clutch of key men ahead of the crucial Atletico Madrid clash was clearly the priority for the Portuguese.
A Madrid double
As expected, Real Madrid opened with fierce attacking pressure on the hosts and came close to an early goal more than once, undone only by wastefulness in front of goal.
The breakthrough finally came in the 26th minute. Arda Guler thumped a superb direct free-kick that struck the right post, grazed Elche keeper Matias Dituro and crept in as an own goal.
Seven minutes later, Kylian Mbappe doubled the lead, finishing a low cross from new arrival Yan Diomande for the Ivorian's first goal contribution.
The pressure kept coming, and four minutes before the break Mbappe found the net again, only for referee Gil Manzano to rule him offside at the moment Fede Valverde threaded a ball through the Elche defence.
Elche fight back
Real Madrid dropped off badly after the interval. Mourinho's changes looked designed to rest more of his players, and the hosts punished him with a goal back.
In the 71st minute, Abel Osorio rose unmarked to steer a Lucas Cebolla cross past Thibaut Courtois with ease, a glaring lapse from the Real Madrid defence.
The equaliser arrived in the 82nd minute. Fernando Nino swept a ball into the far corner, well beyond Courtois's reach.
Espi the rescuer
Just as a draw looked certain, substitute Carlos Espi popped up in second-half stoppage time to grab the winner after a well-worked low pass from Mbappe.
It was not the first time the newcomer had played saviour. He had already snatched a last-gasp win for Real Madrid in the very same fashion against Espanyol on the opening day.
Back then the young Spanish forward came on for the final ten minutes with the score at 1-1 and struck the decisive goal.