Eubank got in on the action next, following an interception by Keelan Johnson with a 29-yard touchdown pass to Coyle in the second quarter, then opened the third by scoring on a 1-yard dive.
Kelly added another score late in the third quarter, scrambling long enough to find Ross for a 31-yard touchdown that put Arizona State up 46-0.
Kelly completed his final 18 passes, setting a school single-game mark for most consecutive completions, topping the mark of 13 set by Dick Mackey vs. S.D. Navy in 1952. He finished with 246 yards on 20 of 23 passing, while Eubank was 7 for 9 for 55 yards.
"It's pretty phenomenal how he's played as a first-year quarterback," Graham said of Kelly.
The big day by Arizona State's quarterbacks added to Washington State's misery in what has been a rough first season under Leach.
After opening with a pair of wins in their first three nonconference games, the Cougars struggled once the Pac-12 season started, losing their first seven games.
It got worse last week when Wilson quit the team, saying the coaches had physically, mentally and verbally abused him.
Leach denied the allegations, just as he did at Texas Tech, where he was fired in 2009 after being accused of abusing a player.
The Cougars vowed not to let Wilson's accusations become a distraction.
They didn't play like it.
Washington State ended its first fruitless drive by bouncing a snap on a punt, setting up Arizona State for a 21-yard field goal. The Cougars didn't get much better from there, managing more punts than first downs (5-4) at one point of the first half while Jeff Tuel and Connor Halliday each threw interceptions.
The Pac-12's passing leader, Washington State threw for 240 yards — 137 below its season average.
"I don't know what happened, but there was a huge change in possession that gave the defense short field early in the game and I feel like that kind of had the sideline's moral go down," Cougars safety Deone Bucannon said. "As a team, and the great teams do it, especially defensively, that needs to bounce off your chest."
It didn't and Arizona State raced off to a big victory for its seniors.