Olson nailed the snap, and the Trojans hit the extra point to give them a 49-31 lead.
The Trojans had quite a moment late in their game against Western Michigan.. Carr added 69 yards and two scores on his seven carries.
USC took the lead midway through the fourth quarter, but then Western Michigan took the ensuing kickoff back for a touchdown to knot the score at 28.
The Trojans will host Pac-12 North rival Stanford next Saturday.
Oxlade-Chamberlain reveals why he left Arsenal for Liverpool
One player who did land a move away was England worldwide Oxlade-Chamberlain, who completed the formalities on his transfer to Liverpool .
Late in the fourth quarter, USC added a final touchdown when safety Marvell Tell picked off a pass and returned it 37 yards.
USC looked to be in trouble against Western Michigan this evening, but eventually, the No. 4 Trojans pulled away.
Long-snapper Jake Olson, who came to many people's attention when he took part in a USC spring game, lost his vision at age 12 as a result of retinal cancer.
This game remained so close for so long because the Broncos, playing their first game under new head coach Tim Lester, performed every bit like the defending MAC champions that they are. USC LB Cameron Smith missed the first half, serving a one-half suspension due to a targeting penalty in January's Rose Bowl.
USC's offense displayed no ills early, at least not on its first drive, reaching the end zone two minutes into the game.