COLLEGE STATION, Texas -- Jerrod Johnson threw three touchdown passes and ran for another score and Texas A&M's offense dominated in the Aggies' 35-10 win over Iowa State on Saturday.

Cyrus Gray rushed for 119 yards and Christine Michael had a touchdown run for A&M (5-3, 2-2 Big 12), which gained 501 yards, went 10-for-13 on third-down conversions and never punted.

Jerome Tiller ran for a touchdown, but threw two costly interceptions for the Cyclones (5-4, 2-3). Tiller, a redshirt freshman, started in place of junior Austen Arnaud for the second straight week. Arnaud is recovering from a bruised throwing hand.

Alexander Robinson, the Big 12's leading rusher, ran for 76 yards on 20 carries after sitting out last week's 9-7 win at Nebraska with a groin injury.

The Aggies marched for touchdowns on their first three possessions and cruised to a 21-3 halftime lead.

Johnson went 5-for-6 on A&M's first drive, then scored on fourth down from the 1-yard line with 4:55 left in the opening quarter. Johnson leads the team with six rushing touchdowns.

A&M safety Jordan Pugh intercepted Tiller near midfield later in the quarter, and Johnson found sophomore Jeff Fuller down the sideline for his 18th touchdown pass of the season. Fuller, who led the Aggies with nine touchdown catches in 2008, was playing his second game since breaking his right leg against Utah State on Sept. 19.

Iowa State drove to the Aggies' 23, but A&M linebacker Kyle Mangan stuffed Robinson on a fourth-and-1. The Aggies then mounted a 16-play touchdown drive, with Gray scoring on a screen pass from Johnson with 3:27 left in the half.

Grant Mahoney kicked a 29-yard field goal on the last snap of the half for Iowa State.

A&M's Lionel Smith fumbled the second-half kickoff and Iowa State recovered. But A&M cornerback Justin McQueen intercepted Tiller at the goal line and the Aggies took over at their own 3.

Michael broke runs of 14 and 11 yards to give A&M room to maneuver and a personal foul on the Cyclones moved the drive into Iowa State territory.

Freshman Uzoma Nwachukwu caught a pass from Johnson inside the 5, but Iowa State safety James Smith landed a helmet-to-helmet hit at the goal line and jarred the ball loose. The Cyclones recovered in the end zone for a touchback and Nwachukwu lied motionless on the field for several minutes before walking off on his own. He came back later in the game.

A&M linebacker Von Miller blocked Mahoney's field-goal try later in the third quarter, but Miller was called offside. Mahoney then missed an attempt from 42 yards.

Johnson threw a 7-yard touchdown pass to Howard Morrow on the third play of the fourth quarter. Tiller finished a quick Iowa State drive with a 4-yard TD run with 12:15 left, but Michael scored on a 7-yard run less than three minutes later.