Mexico’s Ángel de Jesús Camacho placed second and The Czech Republic’s Arnošt Petráček placed third.
Leslie had earlier swum a heat time of 43.44s to qualify for the final.
“A result like that is always the dream,” said Coach Tom Onley.
“We don’t train long course year round so for Cam to do that is really special. Our club back in Whangārei stopped training to watch the race which is pretty awesome, I’m very proud.”
It’s the second medal of the meet for the Whangarei swimmer who picked up silver earlier in the week in the 100m Freestyle (S4).
Leslie is back in the pool overnight NZT, competing in the 50m Freestyle (S4). He’s joined by Tupou Neiufi who’s contesting the 50m Freestyle (S8), Lili Fox Mason is also in action in the 100m Butterfly (S10).