Yoane Wissa bagged a brace off the bench to get Matthias Jaissle off to a flying start as Newcastle United manager.
Filip Ugrinic fired Valencia into an early lead with a curling effort from outside the area. Moments later, Anthony Elanga wrongfully had a goal disallowed before his night was cruelly ended due to a Jose Gaya horror challenge.
The resulting red card allowed the Magpies to take control - with Jaissle proactively making four changes at the break. Wissa and Bazoumana Toure, in particular, proved to be inspired substitutions.
The Toon No.9 scored shortly after the restart and looked lively throughout before combining with Toure late on to seal the victory. Here are your NewcastleWorld player ratings.
1. Lukas Hornicek - 6
A few shaky moments in the first half. Very little he could have done about the opener. Made a few decent stops and will only grow with confidence. | Getty Images
2. Leo Shahar - 6
Did the basics well. Hooked at half-time. Probably needs a loan move but Newcastle are short of full-back options. | Getty Images
3. Malick Thiaw - 7
Given the armband and was rarely tested. Making him skipper on a permanent basis could be a solid shout. | Getty Images
4. Sven Botman - 7
A good block to deny Valencia doubling their advantage. The Dutchman almost headed into his own net from a mix-up with Hornicek moments later. An improvement from the Bristol City horror show. | Getty Images