Striker Cristiana Girelli came off the bench to head an 87th-minute winner in Italy's Women's World Cup opener against Argentina.
Girelli replaced midfielder Giulia Dragoni, who at the age of 16 years and 259 days became one of the youngest players in the tournament's history.
The record belongs to Ifeanyi Chiejine, who was 16 years and 34 days when she played for Nigeria in 1999.
Azzurre manager Milena Bertolini put her faith in youngster Dragoni who only made her debut for the senior side on 1 July, but ultimately it was experienced Juventus player Girelli who made the difference.
It looked as though Italy were going to be frustrated by a gritty defensive performance by Argentina before substitute Girelli, who replaced Dragoni in the 83rd minute, nodded the winner.
The vastly experienced Girelli got on the end of Lisa Boattin's cross and looped the ball over Vanina Correa to secure a 1-0 victory.
In front of a crowd of 30,889 spectators, Italy had earlier seen goals by Arianna Caruso and Valentina Giacinti ruled out for offside.
A tetchy contest which included six bookings was stopped numerous times to allow players to have treatment.
Italy, who also included 18-year-old forward Chiara Beccari from the start, go to Wellington next to play Sweden, who also have three points in Group G, on Saturday (kick-off 08:30 BST).
Argentina's next match is against South Africa in Dunedin on Friday (01:00 BST).
Youngster Dragoni plays her part
Italy have lost their way since an impressive showing at the 2019 World Cup which included wins over Australia, Jamaica and China.
They disappointed at Euro 2022 and 13 of Bertolini's 23 players at this tournament are appearing on the World Cup stage for the first time.
The Italy boss produced a major surprise before kick-off by naming Dragoni in her starting XI - just three weeks after the youngster made her debut for Le Azzurre aged 16 years and 236 days.
She has been nicknamed 'Little Messi' and played her part in her country's win with some confident touches, with the teenager finishing the match with an 86.4% passing accuracy.
While Dragoni started, forward Girelli, defender Elisa Bartoli and midfielder Valentina Cernoia - who have more than 200 caps between them and are appearing at their second World Cup - had to make do with seats on the bench.
Girelli made her presence felt after climbing off the bench to settle the match and break Argentina's hearts.
La Albiceleste thought they had earned themselves a crucial point and looked crestfallen after Girelli struck before Florencia Bonsegundo was denied an equaliser in the closing moments by Francesca Durante.
The hunt for a first World Cup win goes on for Argentina, who have lost eight of their 10 games spanning four editions of the tournament.
Player of the match
DragoniGiulia Dragoni
Italy
Squad number16Player nameDragoni
Squad number10Player nameGirelli
Squad number14Player nameBeccari
Squad number17Player nameBoattin
Squad number9Player nameGiacinti
Squad number7Player nameCantore
Squad number18Player nameCaruso
Squad number4Player nameDi Guglielmo
Squad number20Player nameGreggi
Squad number8Player nameBonansea
Squad number6Player nameGiugliano
Squad number5Player nameLinari
Squad number22Player nameDurante
Squad number23Player nameSalvai
Argentina
Squad number22Player nameBanini
Squad number10Player nameIppólito
Squad number9Player nameGramaglia
Squad number3Player nameStábile
Squad number15Player nameBonsegundo
Squad number16Player nameBenítez
Squad number8Player nameFalfán
Squad number19Player nameLarroquette
Squad number11Player nameRodríguez
Squad number7Player nameNúñez
Squad number6Player nameCometti
Squad number13Player nameBraun
Squad number1Player nameCorrea
Squad number14Player nameMayorga
Line-ups
Italy
Formation 4-2-3-1
22Durante
4Di Guglielmo5Linari23Salvai17Boattin
6Giugliano16Dragoni
8Bonansea18Caruso14Beccari
9Giacinti
22Durante4Di Guglielmo5Linari23Salvai17Boattin6Giugliano16DragoniSubstituted forGirelliat 83'minutes8BonanseaBooked at 85mins18CarusoBooked at 25minsSubstituted forGreggiat 58'minutes14Beccari9GiacintiSubstituted forCantoreat 74'minutesSubstitutes
1Giuliani2Severini3Orsi7Cantore10Girelli11Glionna12Baldi13Bartoli15Serturini19Lenzini20Greggi21CernoiaArgentina
Formation 4-2-3-1
1Correa
13Braun14Mayorga6Cometti3Stábile
8Falfán16Benítez
7Núñez22Banini15Bonsegundo
19Larroquette
1Correa13Braun14MayorgaBooked at 68mins6Cometti3StábileBooked at 90mins8FalfánSubstituted forIppólitoat 90+2'minutes16Benítez7NúñezSubstituted forRodríguezat 77'minutes22Banini15BonsegundoBooked at 76mins19LarroquetteBooked at 12minsSubstituted forGramagliaat 90+2'minutesSubstitutes
2Sachs4Cruz5Santana9Gramaglia10Ippólito11Rodríguez12Esponda17Gómez18Chávez20Singarella21Lonigro23ChávesLive Text
Match ends, Italy 1, Argentina 0.
Second Half ends, Italy 1, Argentina 0.
Corner, Italy. Conceded by Vanina Correa.
Attempt saved. Lisa Boattin (Italy) right footed shot from a difficult angle on the right is saved in the bottom right corner.
Eliana Stábile (Argentina) is shown the yellow card for a bad foul.
Sofia Cantore (Italy) wins a free kick in the attacking half.
Foul by Eliana Stábile (Argentina).
Foul by Sofia Cantore (Italy).
Estefanía Banini (Argentina) wins a free kick in the defensive half.
Hand ball by Paulina Gramaglia (Argentina).
Attempt missed. Sofia Cantore (Italy) right footed shot from outside the box misses to the left. Assisted by Chiara Beccari following a fast break.
Attempt saved. Florencia Bonsegundo (Argentina) right footed shot from outside the box is saved in the centre of the goal.
Foul by Sofia Cantore (Italy).
Florencia Bonsegundo (Argentina) wins a free kick in the attacking half.
Substitution, Argentina. Paulina Gramaglia replaces Mariana Larroquette.
Substitution, Argentina. Dalila Ippólito replaces Daiana Falfán.
Francesca Durante (Italy) wins a free kick in the defensive half.
Foul by Aldana Cometti (Argentina).
Foul by Cristiana Girelli (Italy).
Daiana Falfán (Argentina) wins a free kick in the defensive half.