Newcastle conceded three goals in 18 first-half minutes en route to a 3-1 loss to Malaga at Schalke's Veltins Arena.
Sergi Darder opened the scoring in the 25th minute with a long-range strike that went in off the woodwork.
Samu Castillejo volleyed in at the far post in the 32nd minute and the same man then netted a deflected effort towards the end of the half before Gabriel Obertan fired in a consolation on the hour.
West Ham face the hosts in Saturday's second Schalke Cup clash in Gelsenkirchen, while on Sunday, the Hammers face Malaga and Newcastle take on Schalke.