Leicester were beaten 2-1 by Sevilla in the first leg of their last-16 Champions League clash on Wednesday, but were given hope by Jamie Vardy's away goal.
Pablo Sarabia gave the home side a deserved lead in the 25th minute when he powered a header in off the far post, before Joaquin Correa doubled the advantage in the 62nd minute.
Correa also saw a penalty saved by Kasper Schmeichel in a one-sided first half, while Vitolo and Adil Rami both hit the woodwork after the break.
But Vardy pulled one back for the visitors with their first real foray into the opposition box 17 minutes from time after Danny Drinkwater's superb assist, as Leicester managed to survive an onslaught and escape with only a one-goal deficit.
The goal - Vardy's first in the Champions League - gives the Foxes a lifeline ahead of the return leg at the King Power Stadium on Tuesday, March 14.
The Foxes, who are currently one point above the Premier League relegation zone having failed to score a league goal in 2017, made 10 changes from the starting XI that lost to Millwall in the FA Cup at the weekend, as Vardy, Riyad Mahrez, Schmeichel and Drinkwater returned.
Sevilla started on the front foot with Schmeichel given an early scare in the fourth minute after Sarabia cut inside and fired narrowly over the crossbar from 25 yards.
The hosts - third in La Liga - had an even better opportunity to open the scoring in the 14th minute when Leicester captain Wes Morgan brought down Correa in the box, but his subsequent penalty was saved by Schmeichel low to his right.
The breakthrough eventually arrived with an unstoppable header from Sarabia in the 25th minute, powering in at the back post from Sergio Escudero's left-wing cross.
Jorge Sampaoli's side nearly doubled their advantage when Mahrez carelessly gave away the ball and Vitolo's long-range effort cannoned off Robert Huth but the back-pedalling Schmeichel tipped it over, before saving from Correa as half-time approached.
The second half continued in the same manner as the previous 45 minutes, with Schmeichel again on hand to deny Correa after he had deflected Mariano's effort on goal, before Sergio Rico was forced into his first save at the other end when Wilfried Ndidi's 25-yard volley sailed into his arms.
The visitors survived another scare just moments later, as Samir Nasri sent a sumptuous disguised pass beyond Leicester's offside trap only for Vitolo to stump the foot of the post and see the ball trickle along the goal line.
Sarabia then dragged an effort wide shortly afterwards, but Leicester finally woke up just shy of the hour mark after Ranieri sent on Demarai Gray for the ineffective Ahmed Musa and the substitute's endeavour enabled Drinkwater to strike wide courtesy of a deflection.
Sevilla, though, doubled their advantage when Morgan and Huth were caught out by a routine ball over the top and former Manchester City forward Stevan Jovetic squared to Correa, who finished with aplomb via the underside of the crossbar.
Although Leicester had been outplayed, they grabbed a route back into the tie through their first meaningful attack, as Gray found Drinkwater down the left-hand side and the midfielder played a perfectly-weighted pass across goal for Vardy to finish.
That goal only served to awake Sevilla, who went on the assault to find a third, but once again Schmeichel was on hand to keep the hosts at bay when Vitolo met Sarabia's deflected cross at the back post, before Jovetic's shot went wide.
The woodwork was struck again in the dying minutes as centre-back Rami crashed a header against the bar, but the Foxes held on to ensure they need a 1-0 win in the return leg to advance to the last eight.