Purdue coach Joe Tiller tied Jack Mollenkopf for the most wins in school history with 84. He also beat one of his former assistants -- Northern Colorado coach Scott Downing worked under Tiller for 12 years at Wyoming and Purdue.
Bryan Waggener passed for 216 yards and a touchdown and Ryan Chesla caught nine passes for 99 yards for Northern Colorado (0-1), a Football Championship Subdivision team that went 1-11 last season.
Purdue's first score came on Painter's 26-yard strike down the middle to slot receiver Keith Smith.
In the second quarter, Purdue's Frank Halliburton tipped a Northern Colorado punt, and the Boilermakers took over on the Northern Colorado 37. Two plays later, Sheets' 9-yard touchdown run gave Purdue a 14-0 lead.
On the Boilermakers' next possession, Tardy took a screen pass 60 yards, but Purdue was unable to score from inside the 20. Purdue moved into Northern Colorado territory six times in the first half, but led 14-0 at halftime.
Early in the third quarter, Northern Colorado went for it on fourth-and-5 from the Purdue 30, but Ryan Baker sacked Waggener and the Boilermakers took over.
Halliburton got pressure on another Bears punt after a poor snap, and Purdue took over at the Northern Colorado 34 with about 6 minutes left in the third quarter. Sheets scored again, a 2-yard run that gave Purdue a 21-0 lead with 2:32 left in the third quarter.
Northern Colorado caught a break early in the fourth quarter. The Bears punted to Purdue, and the ball bounced off a Boilermaker player's leg before Northern Colorado's C.J. Stemo recovered at the Purdue 25. Michael York made a 37-yard field goal.
On Purdue's next possession, Painter found Greg Orton down the left sideline for a 43-yard touchdown pass that gave the Boilermakers a 28-3 lead.
Minutes later, Halliburton blocked another punt, and Mike Conway's recovery and runback for a touchdown made it 35-3.
Northern Colorado scored a TD on Waggener's 3-yard pass to Jason Caprioli with 7:08 to play.