The Tigers rushed for 297 yards on 45 carries, divvying up the carries among Mason, Grant and Cameron Artis-Payne.
Malzahn did like Marshall's poise after the early jitters and his calm demeanor in the locker room at halftime despite having completed only 2 of 8 passes.
"There were a couple things communication-wise we'll get better on but overall I liked the way he handled himself," the coach said. "He protected the football and that's hard to do. They were showing him a lot of different looks and trying to disguise some things but he protected the football."
Washington State coach Mike Leach figures one game isn't enough to gauge how Marshall will do.
"I am just kind of curious about him after he gets more games under his belt," Leach said.
Marshall was just one of five first-time starters for the Tigers. Defensive linemen Dee Ford and Jeff Whitaker and defensive back Justin Garrett missed the game with injuries.
Malzahn indicated Whitaker could be out awhile and said he underwent a surgical procedure last week for an unspecified injury. He was using crutches on a visit to the field before the game.
Ford's absence left the Tigers struggling early to mount a pass rush. JUCO transfer Ben Bradley and freshman Montravius Adams had the team's two sacks.
Adams was one of Auburn's top recruits and part of a defensive line group that was the biggest highlight of the signing class.
"It felt great," Adams said. "It was my first play of the game, and I didn't want to let the team down. At the snap of the ball, my only focus was to push down the quarterback, and I did."