Huh. This was just a workout, first workout post-marathon 16 days ago, a chance to check on how my recovery is going. A PR (ties 5K PR from last summer) if the official chip time matches up with my GPS. Very happy with the result, but hopefully didn't overdo it. Less than 3 weeks until next marathon (Grandma's).
MTA: Chip time was 13 sec off Gun time, so 18:49 --> 18:36. I've exactly tied a PR for the second time in less than a year (I ran 1:27:53 two years in a row at Gopher Badger Half Marathon). I ran 18:36 last summer at Torchlight.