Victor Osimhen had missed several chances in the first half before scoring two goals after the breakLeicester were denied victory in their Europa League opener at King Power Stadium after Napoli's Victor Osimhen scored twice in the second half.
Osimhen reduced Leicester's 2-0 lead after 69 minutes with an exquisite touch past Kasper Schmeichel, before his header made it 2-2 late on.
Ayoze Perez had scored a first-half volley and Harvey Barnes doubled Leicester's lead after the break.
Leicester summer signing Patson Daka also had a goal ruled out for offside.
The two sides, widely tipped as being among the favourites to win the competition, delivered an entertaining encounter in front of a vocal crowd at the King Power.
Leicester goalkeeper Schmeichel was called into action on several occasions, while Barnes proved a constant threat at the other end.
The hosts looked set to take pole position in Group C too, but Osimhen dealt a late blow before Leicester's Wilfred Ndidi was sent off for a second booking.
It leaves the group wide open with Leicester still to travel to Italy, as well as facing Spartak Moscow and Legia Warsaw.
Leicester clawed back in enthralling battle
Ayoze Perez was one of five changes to the starting line-up made by Brendan Rodgers for LeicesterThere was a carnival atmosphere at the King Power to welcome European football back to Leicester and the match did not disappoint.
Napoli set the tone with their first shot on target after only three minutes and Leicester responded when Barnes was denied from close range, before setting up Perez's volley with a perfectly-weighted cross.
Timothy Castagne, along with the help of Schmeichel, somehow kept out Napoli's Piotr Zielinski, while Lorenzo Insigne and Hirving Lozano came close.
The Italians had been wasteful and when Barnes coolly thumped in Leicester's second, they looked set to come out on top.
But a sublime one-touch passing move saw Osimhen dance into the box before he flicked the ball past Jannik Vestergaard and over Schmeichel.
And the Napoli forward then hung well in the air to nod in a second and complete the comeback.
Tensions flared following the final whistle as police and stewards intervened after missiles were thrown by both sets of supporters.
Player of the match
OsimhenVictor Osimhen
Leicester City
Squad number7Player nameBarnes
Squad number1Player nameSchmeichel
Squad number14Player nameIheanacho
Squad number6Player nameEvans
Squad number17Player nameAyoze Pérez
Squad number29Player nameDaka
Squad number42Player nameSoumaré
Squad number27Player nameCastagne
Squad number25Player nameNdidi
Squad number23Player nameVestergaard
Squad number5Player nameBertrand
Squad number4Player nameSöyüncü
Squad number37Player nameLookman
Squad number8Player nameTielemans
Squad number9Player nameVardy
Squad number10Player nameMaddison
Napoli
Squad number9Player nameOsimhen
Squad number33Player nameOunas
Squad number5Player nameJuan Jesus
Squad number37Player namePetagna
Squad number24Player nameInsigne
Squad number11Player nameLozano
Squad number21Player namePolitano
Squad number20Player nameZielinski
Squad number26Player nameKoulibaly
Squad number7Player nameElmas
Squad number99Player nameZambo Anguissa
Squad number13Player nameRrahmani
Squad number8Player nameRuiz
Squad number2Player nameMalcuit
Squad number22Player nameDi Lorenzo
Squad number25Player nameOspina
Line-ups
Leicester
Formation 4-3-3
1Schmeichel
27Castagne6Evans23Vestergaard5Bertrand
17Pérez25Ndidi42Soumaré
29Daka14Iheanacho7Barnes
1Schmeichel27Castagne6EvansSubstituted forSöyüncüat 45'minutesBooked at 76mins23VestergaardBooked at 53mins5Bertrand17PérezSubstituted forTielemansat 45'minutes25NdidiBooked at 90mins42SoumaréBooked at 32minsSubstituted forMaddisonat 78'minutes29DakaSubstituted forLookmanat 71'minutes14IheanachoSubstituted forVardyat 87'minutes7BarnesSubstitutes
4Söyüncü8Tielemans9Vardy10Maddison11Albrighton12Ward18Amartey20Choudhury21Ricardo Pereira22Dewsbury-Hall33Thomas37LookmanNapoli
Formation 4-3-3
25Ospina
2Malcuit13Rrahmani26Koulibaly22Di Lorenzo
99Zambo Anguissa8Ruiz20Zielinski
11Lozano9Osimhen24Insigne
25Ospina2MalcuitSubstituted forNunes Jesusat 84'minutes13RrahmaniBooked at 90mins26Koulibaly22Di LorenzoBooked at 33mins99Zambo AnguissaSubstituted forPetagnaat 84'minutes8Ruiz20ZielinskiSubstituted forElmasat 64'minutes11LozanoSubstituted forPolitanoat 64'minutes9Osimhen24InsigneSubstituted forOunasat 74'minutesSubstitutes
5Nunes Jesus7Elmas16Idasiak21Politano33Ounas37Petagna44Manolas59Zanoli72BoffelliLive Text
Match ends, Leicester City 2, Napoli 2.
Second Half ends, Leicester City 2, Napoli 2.
Amir Rrahmani (Napoli) is shown the yellow card for a bad foul.
Foul by Amir Rrahmani (Napoli).
James Maddison (Leicester City) wins a free kick in the attacking half.
Foul by Juan Jesus (Napoli).
Ademola Lookman (Leicester City) wins a free kick in the defensive half.
Second yellow card to Wilfred Ndidi (Leicester City) for a bad foul.
Adam Ounas (Napoli) wins a free kick in the attacking half.
Foul by Wilfred Ndidi (Leicester City).
Attempt missed. Amir Rrahmani (Napoli) header from the centre of the box is too high. Assisted by Matteo Politano with a cross following a set piece situation.
Adam Ounas (Napoli) wins a free kick in the attacking half.
Foul by Youri Tielemans (Leicester City).
Substitution, Leicester City. Jamie Vardy replaces Kelechi Iheanacho.
Goal! Leicester City 2, Napoli 2. Victor Osimhen (Napoli) header from the centre of the box to the top left corner. Assisted by Matteo Politano with a cross.
David Ospina (Napoli) wins a free kick in the defensive half.
Foul by Ademola Lookman (Leicester City).
Corner, Leicester City. Conceded by Amir Rrahmani.
Substitution, Napoli. Juan Jesus replaces Kevin Malcuit.
Substitution, Napoli. Andrea Petagna replaces André-Frank Zambo Anguissa.
