Jamie Vardy and Kasper Schmeichel kept Leicester's Champions League hopes alive as they escaped from Sevilla still eyeing the quarter-finals.
Striker Vardy stunned the hosts with a second-half goal - his first in 748 minutes - as the Foxes fell to a gutsy 2-1 last-16 defeat in Spain.
It came after Schmeichel had saved an early Joaquin Correa penalty and gave Claudio Ranieri's side a crucial away goal after they were outplayed by the hosts in the first leg.
Pablo Sarabia and Correa had put Sevilla into a deserved lead but Vardy's first European goal put a completely different complexion on next month's second leg at the King Power Stadium.
But for Schmeichel's first-half heroics Leicester would have been out of the tie before half-time with Sevilla's lead failing to reflect their utter dominance.
The Dane pulled off a string of saves as the Foxes survived a first-half onslaught but hung on to set up a winner-takes-all showdown on March 14.
Without a Premier League win and goal in 2017, and having been dumped out of the FA Cup by Millwall on Saturday, Leicester were looking to Europe to gain momentum in their domestic relegation fight.
While they were outclassed at the Ramon Sanchez Pizjuan Stadium, Ranieri's men can take heart from the defeat.
Sevilla, looking to reach the Champions League quarter-finals for the first time since 1958, signalled their early intent as Sarabia shot over while Christian Fuchs sparked panic when his header almost caught out Schmeichel.
The hosts' early domination would have been a growing concern to Ranieri with Vardy isolated, eventually having just 10 first-half touches, and having to feed off hopeful long balls.
Schmeichel was the sole piece of resistance as he bailed the Foxes out constantly during the first half - starting with a 15th-minute penalty save.
It all stemmed from poor defending as Robert Huth failed to clear before Wes Morgan chopped down Correra as he went to shoot. It was a clear penalty but Correra wasted the chance as his tame spot-kick was easily stopped by Schmeichel.
The miss failed to dampen Sevilla's desire to bury Leicester early and Sergio Escudero was the next to be denied by Schmeichel - before they finally beat the Dane after 25 minutes.
The hosts had started to slice through the Foxes after the penalty miss and this time Escudero's delicious cross did the damage as Sarabia rose above the hapless Fuchs to plant a brilliant header in off the far post.
It was the first time Schmeichel had conceded in the Champions League this season and he was forced into action less than a minute later when he turned Stevan Jovetic's deflected effort over.
The onslaught continued as leggy Leicester were second to everything, unable to cope with Sevilla's relentless pace and pressure which should have yielded more than one goal.
Schmeichel stopped Correa from making it 2-0 with another low stop nine minutes before the break as Leicester survived further first-half trouble as Vitolo headed over in added time.
Ranieri won the Copa del Rey with Valencia in Sevilla in 1999 but he had little to cheer as Vitolo almost made it 2-0 five minutes after the break when his shot from the tightest of angles brushed the face of the post.
It came after Wilfred Ndidi had at least tested underemployed Sevilla goalkeeper Sergio Rico before Correa made up for his penalty miss after 62 minutes.
Again it was too easy as Jovetic was allowed to bully his way onto a bouncing ball in the box and he slipped in Correa to fire in off the bar from six yards.
That was the game won and the hosts went looking for a third which would likely kill off the tie but they were stunned when Vardy pulled a goal back with 17 minutes left.
Demarai Gray and Danny Drinkwater combined on the left for Drinkwater to break free and cross for Vardy to convert his first goal since December 10 from close range.
The hosts were rattled but Schmeichel still needed to save from Vitolo with seven minutes left and Adil Rami hit the bar late on.