The senior rushed for 140 yards and a score as the incumbent Pac-12 South champion Buffaloes (1-0) began their title defense by dropping the rival Rams in front of a record crowd of 73,932 on Friday night in Denver.
Lindsay, whose father Troy played was a fullback at Colorado State, earned the seventh 100-yard rushing game of his career, reaching the mark in the first half (101 yards).
Colorado State made a late push, but had a drive stall on the Colorado 39-yard line after Trey Udoffia stripped Rams wide receiver Warren Jackson for a fumble recovered by Afolabi Laguda. Udoffia added an interception on Colorado State next drive to end the game.
Quarterback Steven Montez was efficient, connecting on 21 of 29 passes for 202 yards and a touchdown. The sophomore threw two picks, both to Kevin Nutt Jr.
Those expecting a shootout were disappointed by the Colorado defense, which picked up where it left off last year, despite having eight new starters.
Colorado used its quick offense to build a 17-3 halftime lead on a Lindsay 45-yard scoring run and a 31-yard touchdown grab by senior Shay Fields. The Buffaloes defense preserved that lead heading into the break, courtesy of a pair of tackles-for-loss by Jacob Collier and Laguda on the half's final two plays to quash the late Colorado State drive.
Colorado State was its own worst enemy between poor blocking and 10 penalties for 120 yards --including three offensive pass interference calls, one of which nullified a Detrich Clark score in the third quarter. The Rams offense had another touchdown called back a play later after an illegal hands-to-the-face call reversed a 40-yard Olabisi Johnson score.
Stevens completed the meltdown on the next play by throwing an interception to Evan Worthington. The pick marked the 19th consecutive game in which the Buffs forced a Rams turnover.
Stevens threw for 309 yards.
Colorado linebacker Rick Gamboa led all tacklers with 10 take-downs, including one of the team's two sacks.
James Stefanou, a 30-year old former Australian soccer player, connected on a 39-yard field goal and pushed a 38-yard attempt wide right with 6:03 remaining in the game.