Newcastle took an early lead courtesy of Callum Wilson who tucked home an effort after great work from Allan Saint-Maximin and Matt Ritchie in the build-up.
The visitors grew into proceedings but it was the Magpies who deservedly led at the break, a lead they would double soon after thanks to Saint-Maximin.
The winger was sent through one-on-one with Ander Iruarrizaga in the Bilbao goal and coolly slotted home an effort into the bottom conrer.
The visitors responded through a Raul Garcia header after the hour mark and pressed for an equaliser but just couldn’t beat Martin Dubravka as the Newcastle defence stood tall.
The result made it back-to-back wins at home for the Magpies ahead of their season opener with Nottingham Forest.
Here are our Newcastle United player ratings from the clash with Athletic Bilbao at St James’s Park:
5. Paul Dummett - 7
Was very solid in defence and dealt with everything thrown his way. Taken off after 70 minutes. Photo: Stu Forster
6. Joe Willock - 8
Linked-up well with Wilson up-front and enjoyed success with some driving runs forward from midfield. Had a quiet second-half but showed a lot of promise in the first 45. Photo: Gualter Fatia
7. Bruno Guimaraes - 6
Started the game like a man on a mission and controlled the midfield throughout the first-half. Had a quiet second period and looked frustrated as things didn’t seem to click for him. Subbed just before the final whistle. Photo: Gualter Fatia
8. Joelinton - 7
Lovely little chip over the defence released Saint-Maximin for his goal. Another tough-tackling and all action display from the Brazilian. Photo: Gualter Fatia