The win was expensive as Washington State lost starting quarterback Jeff Tuel to a fractured left clavicle.
Washington State scored on its first four possessions against the Bengals of the FCS, jumping to a 23-0 lead after the first quarter and 40-0 at halftime.
Idaho State lost its 11th game in a row, dating to last season. The loss ruined the debut of Idaho State coach Mike Kramer, who was an assistant last season to Washington State coach Paul Wulff.
Junior college transfer Kevin Yost, making his first start at quarterback for Idaho State, completed 32 of 45 passes for 386 yards, with one touchdown. Rodrick Rumble had 10 catches for 218 yards.
Lobbestael, a senior, completed his first nine passes and finished 14 of 19 in WSU’s most dominant win since beating FCS Portland State 48-9 in 2008. The Cougars piled up 590 yards against outmanned Idaho State, which was 1-10 last season.
Marquess Wilson caught four passes for 91 yards for WSU. Freshman Marcus Mason rushed six times for 88 yards as the Cougars produced 289 rushing yards.
The game was a chance for Washington State to show it is improving after posting a 5-32 record in Wulff’s first three seasons.
Washington State has never lost to an FCS team in 16 outings.
The last time Idaho State beat a major college team was Utah State in 2000, and they have lost 15 in a row since. They have lost 28 straight road games, last winning at Northern Colorado in 2006.
Washington State took the opening kickoff and went 58 yards in five plays, with Rickey Galvin scoring on an 11-yard run.
Lobbestael hit Isiah Barton on a 27-yard touchdown pass on WSU’s second possession.
Tavoy Moore fumbled the ensuing kickoff and Bennett Bontemps recovered for WSU at ISU’s 30. Tuel took over for Lobbestael and the Cougars settled for a 23-yard field goal by Andrew Furney and a 17-0 lead. Tuel did not start the game because of a stomach virus, and only played this one series. It was not immediately clear when he was injured.
Team spokesman Bill Stevens said it is not known how long Tuel will be out of action. Tuel, a junior, threw for 2,780 yards and 18 touchdowns last season.
Idaho State drove to WSU’s 36 on the next possession, but Yost was intercepted by linebacker Alex Hoffman-Ellis, who returned the ball 67 yards for a touchdown and a 23-0 WSU lead.
With Lobbestael back, WSU drove 74 yards on its next possession, with Galvin rushing the final seven for a 30-0 lead.
Furney kicked a 51-yard field goal and Marquess Wilson caught a 61-yard touchdown pass for a 40-0 halftime lead. It was WSU’s biggest halftime margin since they led SW Louisiana 56-0 in 1997.
After the Cougars went up 47-0, Idaho State finally scored when Jahmel Rover ran in from 3 yards to cap a 73-yard drive with 8:53 left in the third. Rover ran in a second touchdown with 4:21 left in the third to bring Idaho State within 54-14.
Mason added a 65-yard touchdown run for WSU. It was the first time WSU has scored 60 points in a game since a 77-7 win over SW Louisiana in 1997.