Jamie Vardy was on the scoresheet once again as Leicester continued their 100 per cent record in Group G with victory over AEK Athens.
The 33-year-old scored from the spot in the 18th-minute - his second goal in four days having netted the winner against Arsenal on Sunday - after he was upended by goalkeeper Panagiotis Tsintotas.
Hamza Choudhury marked his first European start with a goal six minutes before half time to set Leicester well on their way to a third victory in a week after a ruthless 45 minute display.
The hosts made two changes at the break, with striker Muamer Tankovic making an instant impact as he halved the deficit with a smart finish with his first touches, and a minute later the substitute squandered a gilt-edged opportunity.
Cengiz Under struck the post with a fine curling effort as he was denied a goal on his first start in Leicester colours.
But in the end it mattered little as the Foxes held on to claim their second victory from two Group G games.
Leicester are back in action on Monday night when they travel to Leeds in the Premier League.
TALKING POINT - Vardy leads Leicester to victory
The absence of Vardy was severely felt as Leiciester suffered a recent dip in form with a calf injury. With his pace and clever movement, the 33-year-old adds a dimension to Leicester's attack which simply can't be replicated. After netting the winner at the Emirates, Vardy was up to his old tricks again, slipping in behind the home defence to draw the AEK goalkeeper off his line and win the penalty, which he coolly converted.
With Maddison finally match fit after his own injury troubles, and Under finally beginning to show signs of his potential, Leicester are in a good position to kick on after a bright start to the campaign, even if this wasn't a vintage performance.
Three wins in a week and another away victory under their belt, the Foxes are building momentum.
MAN OF THE MATCH - Jamie Vardy (Leicester)
A typical performance from the veteran striker, who led the line effectively until he was replaced with 20 minutes remaining.
AEK Athens: Tsintotas 5, Bakakis 6, Svarnas 5, Nedelcearu 5, Insua 6, Shakhov 5, Krsticic 6, Livaja 5, Mantalos 7, Helder Lopes 5, Ansarifard 5.. subs: Tankovic 7, Nelson Oliveira 5, Sabanadzovic N/A, Machairas N/A, Vasilantonopoulos N/A
Leicester: Schmeichel 6, Albrighton 6, Fofana 7, Morgan 8, Fuchs 6, Justin 6, Choudhury 7, Tielemans 7, Under 7, Maddison 7, Vardy 8.. subs: Thomas 6, Mendy 5, Praet 5, Barnes 5, Iheanacho 5.
18' - GOAL! AEK Athens 0-1 Leicester (Jamie Vardy, pen): Not the most of convincing of spot-kicks from Vardy as Tsintotas gets a hand to it, but he can't keep it out! Leicester are ahead!
39' - GOAL! AEK Athens 0-2 Leicester (Hamza Choudhury): Maddison's corner delivery misses everyone at the near post and falls to Choudhury at the back post. He watches it all the way and fires a lovely volley past the goalkeeper at his near post, as he marks his first European start with a goal!
49' - GOAL! AEK Athens 1-2 Leicester (Muamer Tankovic): Tankovic, who replaced Livaja at the break, halves Leicester's lead with his first touches! He races onto Mantalos' through ball and smashes it past Schmeichel!
50 ' - AEK should be level! It's that man Tankovic once again who gets in behind the Leicester defence, and once more he's released by Mantalos. This time, however, he shoots over the bar when through one on one with the Leicester keeper!
64' - Off the post! A brilliant effort by Under, who bursts into the penalty from the right and bends a delicious shot at goal. It crashes off the post and bounces to safety.
- Jamie Vardy (33 years and 292 days old) has become Leicester's oldest ever scorer in major European competition.
- Vardy has both won (four) and scored (five) more penalties in all competitions than any other player for a top five European league side this season.