49ers Edge Raiders in Preseason Snoozer as DarkHorse Under Cashes Easy

The 49ers limped past the Raiders 18-12 Friday night in a preseason finale that played out exactly as advertised: boring, conservative, and mercifully low-scoring. DarkHorse's under 38.5 never broke a sweat, cruising home with 30 points to spare as both sidelines looked like they'd rather be anywhere else. San…