STILLWATER - Third-string quarterback Brock Purdy completed 18 of 23 passes for 318 yards and four touchdowns to help lead Iowa State to a 48-42 victory over No. 25 Oklahoma State on Saturday.

Purdy, a true freshman, had played just one series before this game. But he stepped in for Zeb Noland -- who was starting his fourth straight game in place of injured starter Kyle Kempt -- in the contest's second series and immediately sparked Iowa State (2-3, 1-2 Big 12 Conference). He also had a rushing touchdown.

The Cyclones entered the day ranked last in the Big 12 in both scoring (17.5 points per game, 122nd in the nation out of 130) and yards (299.5 per game, 123rd overall) but reached season highs in both categories, amassing 465 yards overall.

With Iowa State missing leading rusher David Montgomery because of an upper body injury, Purdy also led the Cyclones in rushing. He had 84 yards, including a 29-yard TD run, on 19 carries.

Tyler Cornelius was 19 of 33 passing for 289 yards and four touchdowns for Oklahoma State (4-2, 1-2), which lost its second consecutive home game. The Big 12's leading rusher, Justice Hill, was limited to 66 yards and one touchdown on 24 carries, a 2.8-yard average.

Purdy and Cornelius had one interception apiece.

TAKEAWAY

Iowa State: The Cyclones just needed an effective quarterback to get their offense going. In addition to Purdy, the Iowa State backup running backs also stepped up in Montgomery's absence. Kene Nwangwu, who was listed as the fourth stringer, had 49 yards on 10 carries.

Oklahoma State: There is some frustration among the home fans with the offensive line's inability to protect Cornelius adequately on passing plays, allowing seven sacks, and to block on rushes. And Hill, who rushed for 189 yards last week and topping 100 in four of the previous five games this season, went just eight yards in his longest run in this one.

UP NEXT

Iowa State: The path doesn't get any easier for the Cyclones, as they return home to take on No. 9 West Virginia.

Oklahoma State: After losing two straight at home, the Cowboys might be glad to go back on the road next week, facing Kansas State