The Cowboys (4-1, 1-0 Big 12) played without All-America receiver Dez Bryant, who was ruled ineligible by the school this week for lying to the NCAA about contact he made with a former NFL player. Oklahoma State was also missing Kendall Hunter, the Big 12's leading rusher in 2008, who sat out with an ankle injury.
Robinson completed 14 of 25 passes for 279 yards, Keith Toston ran for 130 yards and Beau Johnson ran for two scores as the Cowboys won at Kyle Field for only the second time since 1983.
Jerrod Johnson threw three touchdown passes for the Aggies (3-2, 0-1) and set a Big 12 record by extending his streak of consecutive passes without an interception to 228. But Johnson faced constant pressure and the Aggies, who came in with the nation's second-ranked offense, were held to 382 yards.
Leading 29-25 early in the fourth quarter, the Cowboys put it away with a 16-play, 93-yard touchdown drive that chewed up almost eight minutes. Robinson converted two third downs with long passes and Beau Johnson scored with 7:15 left in the game.
Jerrod Johnson found Howard Morrow in the end zone with 3:35 left, but the two-point conversion try failed and A&M trailed 36-31. Oklahoma State regained possession and Toston picked up two yards on a fourth-and-1 with two minutes left.
Robinson went 6-for-14 with an interception in the first half, then completed three of his first five throws in the third quarter, including a 51-yard touchdown pass to Tracy Moore.
Oklahoma State was whistled for two personal fouls on A&M's next series, setting up the Aggies inside the 10-yard line. Freshman Christine Michael scored on a third-down run to put A&M back on top.
Perrish Cox, who missed the Cowboys' last game with a sprained shoulder, returned the ensuing kickoff 45 yards to midfield. After Robinson completed a 32-yard pass to Justin Blackmon, Beau Johnson scored on a 1-yard run and Toston added a two-point conversion run for a 29-22 lead.
Randy Bullock booted a 50-yard field goal on the first play of the fourth quarter, the longest by an A&M kicker since 2000.
The Cowboys drove to the A&M 6 in the first quarter, but a pack of Aggies stuffed Robinson at the line on fourth-and-1. Oklahoma State started its next series at midfield and Toston took a screen pass 40 yards to the A&M 3, setting up Robinson's touchdown run.
The Aggies drove inside the Cowboys' 10 early in the second quarter and came away empty when Bullock hooked a 32-yard field-goal try.
Jerrod Johnson scampered 12 yards for a first down on A&M's next possession. Under pressure again, Johnson found Uzoma Nwachukwu over the middle for a 28-yard touchdown. Receiver Ryan Tannehill, the holder on extra-point kicks, bobbled the snap and ran to the end zone for an unplanned two-point conversion.
Later in the second quarter, A&M got help from a pass interference call and Johnson threw a 15-yard touchdown pass to Jamie McCoy. Less than two minutes later, Robinson threw a 27-yard touchdown pass to Hubert Anyiam.