Mariota amassed 113 rushing yards -- also going 12-of-21 for 234 passing yards and a score -- while Thomas picked up 128 yards on 18 carries for the Ducks (1-0), who amassed a school-record 772 total yards.
Some 500 of them came on the ground as Oregon, coming off a 12-1 record in 2012, got the new season off to a resounding start in the debut of Coach Mark Helfrich, who took the helm after Chip Kelly left to lead the NFL's Philadelphia Eagles.
Kalen Henderson completed 21-of-40 throws for 214 yards in relief of starter Beaux Hebert for Nicholls State (0-1).
Hebert left in the first quarter after absorbing a blow to the head.
Celebrity Families of 2014 [PHOTOS]