From one small spark can come a mighty blaze.
 
[Poca favilla gran fiamma seconda.]

Dante Alighieri (1265-1321) Italian poet

The Divine Comedy [Divina Commedia], Book 3 “Paradiso,” Canto 1, l. 34 (1.34) (1320) [tr. Musa (1984)]
    (Source)

Dante, in a metaphorical prayer to Apollo, hoping his meager efforts describing Paradise will inspire better ones from future poets. The phrase has become proverbial in Italy.

(Source (Italian)). Alternate translations:

From a small spark
Great flame hath risen.
[tr. Cary (1814)]

The spark comes first, and then a mighty flame.
[tr. Bannerman (1850)]

A little spark is followed by great flame.
[tr. Longfellow (1867)]

A mighty flame follows a little spark.
[tr. Butler (1885)]

Great flame may follow from a spark but brief.
[tr. Minchin (1885)]

Great flame follows a little spark.
[tr. Norton (1892)]

A mighty flame followeth a tiny spark.
[tr. Wicksteed (1899)]

A great flame follows a little spark.
[tr. Sinclair (1939)]

A small spark kindles a great flame beyond.
[tr. Binyon (1943)]

From one small spark springs up a mighty flare.
[tr. Sayers/Reynolds (1962)]

Great flames are kindled where the small sparks fly.
[tr. Ciardi (1970)]

A great flame follows a little spark.
[tr. Singleton (1975)]

A little spark brings a great flame after it.
[tr. Sisson (1981)]

Great fire can follow a small spark.
[tr. Mandelbaum (1984)]

A tiny spark can result in a great flame.
[tr. Durling (2011)]

A great flame follows a tiny spark
[tr. Kline (2002)]

A minute spark precedes a towering flame.
[tr. Kirkpatrick (2007)]

Great fire leaps from the smallest spark.
[tr. Hollander/Hollander (2007)]

Tiny sparks can produce a noble flame.
[tr. Raffel (2010)]

A little spark, later a great flame.
[tr. Bang (2021)]