Muema had 105 yards on 14 attempts, and Katz was 16 of 22 passing for 181 yards for the Aztecs (4-3, 2-1 Mountain West), who were not penalized in a game for the first time since 1973.
Conner Smith was 18 of 22 for 165 yards and an interception for the Rams (1-6, 0-3).
SDSU converted all three of Colorado State's turnovers into touchdowns, and scored another TD after the Rams gave the ball up on downs.
On the first play from scrimmage in the second half, Marquise Law fumbled for Colorado State, and Jake Fely recovered for the Aztecs. Two plays later, Katz scrambled to the end zone from 11 yards out to give SDSU a 24-7 lead.
Largent had two interceptions and Fely two sacks for the Aztecs, who have won seven of the last eight meetings between the teams.
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A UCLA football player was suspended indefinitely Friday after he was arrested on suspicion of rape.
Perry Hills will start at quarterback Saturday for Maryland against top-ranked Ohio State, the latest development in the three-way battle to be the Terrapins' starter under center.
The tougher tests await down the road for No. 3 Baylor Bears, but coach Art Briles has seen enough of his Bears to know this is his best team.
A decision has been made that Randy Edsall will not be the football coach at Maryland next season, and discussions are taking place about how and when to separate, a source said Thursday night.
Florida State running back Mario Pender has been released from the hospital but could be given a medical redshirt if he cannot return to the field this season.
The University of Wisconsin agreed to a 10-year deal with Under Armour on Friday worth a total of $96 million in cash and the retail value of products received.