The Fighting Sioux (5-4) trailed 17-3 with 1:37 remaining in the first half but scored two touchdowns in the final 33 seconds to tie the game before adding 10 points in the third quarter to take a 27-17 lead.
The Raiders (2-7) pulled to within 27-24 with 14:53 left on a 6-yard touchdown run by Brandon Baldwin (132 rushing yards) but couldn't get any closer. Hellevang's field goal with 35 seconds left capped the scoring.
Landry's touchdown passes just before the half came 18 seconds apart. His first was a 6-yard strike to Ismael Bamba. On the ensuing kickoff, Ross Cochran returned a fumble to the Raiders' 3. Two plays later, Landry hit Catlin Solum from 2 yards out.