Lafayette built an early lead on Princeton on Saturday, but couldn't hold on in a 42-26 loss at Princeton Stadium.
The Leopards scored three touchdowns in the first quarter to take a 20-11 lead.
But the Tigers outscored Lafayette 33-6 the rest of the way to earn the win.
Ross Scheuerman ran for 162 yards and 3 touchdowns on 22 carries for the Leopards.
Mark Ross had six catches for 112 yards.
Lafayette falls to 1-4 with the loss. They'll visit Harvard next Saturday.