The coach is scheduled to meet Sunday with TCU's chancellor to discuss Pachall, who eight months before his arrest this week admitted to police that he smoked marijuana and failed a team-administered drug test.
Boykin was 23 of 40 passing for 270 yards with one score. He had three interceptions, one on his first pass of the game before two more in the fourth quarter.
Freshman B.J. Catalon had 13 carries for 86 yards, but had two fumbles — one inside the Iowa State 5. Senior running back Matthew Tucker didn't play because of a left ankle injury.
Jaden Oberkrom had field goals of 38, 50 and 39 yards for TCU, which lost for only the second time its last 30 home games.
The Cyclones trickery came late in the third quarter when after taking a handoff on a reverse Lenz stopped and threw a 15-yard score to tight end Ernst Brun. That capped a 10-play drive aided by two personal foul penalties, including a late hit by standout end Stansly Maponga that wiped out a fourth-and-9 for Iowa State.
Still, the Cyclones never trailed after the fourth play of the game, when Barnett avoided a near turnover when he made contact with his running back on play action before hitting Lenz in stride for the touchdown.
"The play didn't start the way you wanted it do," coach Paul Rhoads said. "On plays like that, focus tends to heighten a little bit. ... He delivered a very accurate ball to end the play. Where the ball went is where the ball was supposed to go."
Steele Jantz, the senior quarterback Barnett replaced in the lineup, had one carry for 7 yards.
Despite temperatures in the 50s, Boykin was dealing with leg cramps. He stayed on the ground after rolling right and throwing a 28-yard pass to Brandon Carter early in the fourth quarter.
When Boykin returned for the next series, Irving had his interception after swatting the pass and grabbing it out of the air. The Frogs had the ball one more time, but Knott picked off a pass near the goal line and got to the 36 before running out of bounds into the Iowa State bench area.
"I had intentions of bringing it all the way back," Knott said. "I heard the sideline say get out of bounds. I made the right decision."
Yep, the Cyclones had another big victory, the kind they are getting used to having.