AMES, Iowa (Ticker) -- Zac Calvin tossed a six-yard touchdown pass to Daniel Graham with 11 seconds remaining in the first half as Colorado posted its 16th consecutive victory over Iowa State, 16-12, in a Big 12 Conference North game.

Calvin completed 14-of-23 passes for Colorado (4-3, 3-1 Big 12 North), which rebounded from last week's loss against Texas Tech. Cortlen Johnson rushed for 185 yards on 31 carries, including a four-yard touchdown run that gave the Buffaloes a 10-7 lead with 6:38 remaining in the first half.

Iowa State (4-3, 1-3) went up, 12-10, on Sage Rosenfels' 21-yard TD pass to J.J. Moses, but Colorado answered with a five-play, 49-yard drive, taking a four-point halftime lead on Graham's TD reception. The defenses dominated in a scoreless second half.

Mike McKnight coverted field goals of 42 and 35 yards in the first quarter to give the Cyclones a 6-0 lead. Iowa State held a 379-296 edge in total offense.

Ronsenfels was 16-of-27 for 184 yards for Iowa State while Darren Davis, the nation's No. 4 rusher, ran for 172 yards on 33 carries.

The Cyclones have dropped three of four after opening the season with three wins and fell to 11-42-1 in the all-time series, losing here to Colorado for the eighth straight time.