Burnley's unbeaten pre-season record has been ripped up as they lost 2-0 at KRC Genk.
An eighth-minute goal from Yira Sor and a late hit from Tolu Arokodare saw the Belgians over the line on a frustrating evening for Vincent Kompany.
James Trafford made his debut between the sticks for the Lancashire outfit after signing for £19m from Manchester City but could not carry his clean sheets record from the U21s Euros into this game.
Striker Zeki Amdouni, who recently signed from Basel after 22 goals there last season, came on as a substitute, while Andros Townsend featured as a trialist.