Lazio have now won seven Coppa Italia trophies - only Juventus (13) and Roma (9) have more
Lazio found two late goals to win the Coppa Italia final and deny Atalanta their first trophy since 1963.
On a filthy wet night in Rome both sides struggled to find any fluent football, although Atalanta twice hit the post.
Midfielder Sergej Milinkovic-Savic came off the bench to head in the opener before forward Joaquin Correa ran clear to wrap it up in stoppage-time.
Lazio will now play in next season's Europa League.
Fourth-placed Atalanta can still secure Champions League football for the first time if they win their last two games - against Juventus and Sassuolo.
But their chance of silverware is gone for another year as Lazio edged an ill-tempered game littered with bookings.
Former Liverpool midfielder Lucas would have been an unlikely scorer but headed wide for Lazio before former Middlesbrough midfielder Marten de Roon rattled the post for Atalanta.
Papu Gomez hit the post with a miscued cross as Atalanta continued to look the better side, before sub Milinkovic-Savic scored with Lazio's first effort on target when he headed in Lucas' corner.
Then, as Atalanta threw men forward Lazio broke and Correa did well to dance around goalkeeper Pierluigi Gollini and score.
Seven-time winners Lazio last won the cup in 2013.
-
Line-ups
Match Stats
Line-ups
Atalanta
95Gollini
5MasielloBooked at 36mins
6Palomino
19Djimsiti
33Hateboer
11FreulerBooked at 79mins
15de RoonSubstituted forPasalicat 85'minutes
21CastagneSubstituted forGosensat 85'minutes
10Gómez
72Ilicic
91ZapataBooked at 41minsSubstituted forBarrowat 84'minutes
Substitutes
1Berisha
7Reca
8Gosens
17Piccoli
22Pessina
23Mancini
31Rossi
41Ibañez da Silva
70Colpani
78Del Prato
88Pasalic
99Barrow
Lazio
1Strakosha
3Ramos Marchi
33Acerbi
15Jacinto QuissangaBooked at 24minsSubstituted forRaduat 36'minutes
77MarusicBooked at 87mins
16Parolo
6LeivaBooked at 57mins
10Romero AlconchelSubstituted forMilinkovic-Savicat 79'minutes
19LulicBooked at 39mins
11Correa
17ImmobileSubstituted forCaicedoat 67'minutes
Substitutes
4Gabarrón Gil
13Fortuna dos Santos
14Durmisi
20Caicedo
21Milinkovic-Savic
23Guerrieri
24Proto
25Badelj
26Radu
27Orestes Caldeira
30Lomba Neto
32Cataldi
Referee:
Luca Banti
Match Stats
Home TeamAtalantaAway TeamLazio
Possession
Home53%
Away47%
Shots
Home13
Away12
Shots on Target
Home2
Away3
Corners
Home4
Away8
Fouls
Home11
Away16
Source: bbc.com