The Wildcats held the Cougars to just 174 total yards.
Foles apparently has a dislocated knee cap. Coach Mike Stoops said he doesn't believe it will end his season, though Foles could be out a few weeks. Former USC quarterback Mark Sanchez suffered a dislocated knee camp during fall camp in 2008 and he was still able to start the opener three weeks later.
Matt Scott took over for Foles and completed 13-of-18 for 138 yards with an interception.
For Washington State, it was another competitive performance. The Cougs lost to Arizona 48-7 last year. But the end result is falling to 1-6 on the year and 0-4 in the Pac-10. Things don't get any easier: Up next is a visit to Stanford.
No. 17 Arizona improves to 5-1 and 2-1. The Wildcats play host to Washington next weekend.