The contest was close throughout, Jehuu Caulcrick's two-yard touchdown run early in the fourth quarter put MSU up 24-7 but Idaho answered back to make it 24-17.
After a failed series by the Vandals, Drew Stanton led a time-consuming drive down the field, ending with a 23-yard field goal by freshman kicker Brett Swenson with under a minute remaining.
Swenson made his Spartan debut and greeted the Spartan faithful by making a 35-yard field goal in the second quarter. Overall, Swenson was 2-3 in field goals attempts, missing a 50-yard attempt, and was perfect in extra point conversions.
Spartans led 17-3 at halftime and seemed well on their way to yet another season-opening victory, but Dennis Erickson's Vandals came out in the second half and shut down the Spartan offense while scoring a touchdown of their own on a 1-yard rush from Jayson Bird.
The game was never out of reach for the Vandals, who stopped the Spartans on a fourth down attempt in the fourth quarter to take over on downs.
The Spartans spread the ball around well, with 176 yards on the ground and 224 in the air. Javon Ringer rushed for 70 yards and Caulcrick for 48 yards and each had a touchdown on the day.
In a game where both head coaches have a history of coaching together, their first ever matchup against each other turned out to be a very competitive game, proving that John L. Smith and Dennis Erickson know each other's coaching styles pretty well.
MSU is now 1-0 on the early season and hosts Eastern Michigan next Saturday, while the Vandals travel to Washington State next week. Dennis Erickson coached the Cougars before taking an NFL job with the San Francisco 49ers.