UC Davis (3-4, 2-2 Big Sky) used a balanced attack, including 309 yards and 3 TDs through the air and 338 yards and 4 TDs on the ground.
Redshirt freshman Courtney Williams rushed for 84 yards and 3 TDs, including a 55-yarder in the first quarter.
"I knew what the play was designed to do and it worked," Williams said of his first-quarter score. "The defense took the bait."
UC Davis' Randy Wright passed for 309 yards and 3 TDs.
Idaho State (1-5, 0-3) managed to keep up with UC Davis in the first half and early in the third, but began to fade.
Yost's performance was about the only thing UC Davis coach Bob Biggs could point to when considering areas in which his team may have come up short.
"We knew they were going to throw the ball and we couldn't get as much pressure as we hoped we would," Biggs said.
Despite pulling away to a 14-point lead early in the fourth quarter and forcing Idaho State to punt in their next possession, UC Davis wasn't able to turn its back on the Bengals. With nearly 12 minutes left in the game, Wright threw his only interception of the game.
It was deep in UC Davis territory and put Idaho State on the Aggies' 14-yard line. It took Yost just one play, a 14-yard pass to receiver Luke Austin, to bring the Bengals within a TD.
But the Aggies' next drive proved to be a prime example of Biggs' game plan -- using depth at running back to set up his passing game. The Aggies, starting from their 8, ran five consecutive running plays, taking the ball to their 34.
That's when Wright threw a 41-yard bullet down the middle of the field to receiver Alex Cannon. It was his only catch of the day and put the Aggies on Idaho State's 13-yard line. Four plays later, it was Williams taking it in from the 2-yard line for his third TD of the game.
Jordy Joseph pass intercepted for a TD Kolton Shindelar return for 89 yds for a TD
Devin Chafin run for 4 yds to the 50 yard line for a 1ST down
Jordy Joseph pass intercepted for a TD Craig Suits return for 28 yds for a TD (Redford Jones KICK)
Zack Langer run for 1 yd for a TD
Chad President pass complete to Keyarris Garrett for 37 yds to the Tulan 43 for a 1ST down
C. Johnson sacked by J. Carraway for -2 yds,C. Johnson fumbled, forced by J. Carraway, recovered by TCU D. Pierson
Chris Johnson sacked by Josh Carraway for a loss of 2 yards to the TCU 22 Chris Johnson fumbled, forced by Josh Carraway, recovered by TCU Davion Pierson , return for 0 yards