I'd say the secondary did a decent job. They weren't outstanding, but they were also up against what I thought was a good QB when he actually had time to throw. The coverage was pretty decent, a fair number of times there was nowhere for the QB to really throw.
We did very well at putting pressure on their QB, which helped our pass defense a lot. He was running for his life during most of the game and having to rush throws. Obviously that helps our secondary out a lot.
I still say our secondary has a lot of room for improvement, but to me they looked better than last year.
Edit - I should also say I don't think Nevada had too many YAC's. When they did complete a pass, it seemed like our guys were usually right there to close them down, which is a good thing obviously.