The home side took the lead in the latter stages of the first period when Jonas converted from close range.
The Brazilian had his second in the early stages of the second half as he thumped a powerful volley past Andres Fernandez, before completing his treble with a curling finish five minutes later.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
VALENCIA: Alves; Barragan, V. Ruiz, Mathieu, Guardado; Romeu, Parejo; Feghouli, Canales, Bernat; Jonas
OSASUNA: Fernandez; Bertran, Loties, Arribas, Damia; Cejudo, Lolo, Punal, Armenteros, De las Cuevas; Riera