Antolin ran for 92 yards and two touchdowns, and Grigsby added 66 yards and another score as the Wildcats beat Washington State 24-7 Saturday to remain in contention for the Pac-10 title.
Foles, the league's leading passer, will be out at least two weeks with a sprained knee, coach Mike Stoops said. Backup Matt Scott played nearly three quarters against the Cougars.
"You always have two quarterbacks ready," Stoops said. "Matt was OK, a little rusty."
Arizona (5-1, 2-1 Pac-10) ran 47 times for 142 yards, far above the averages for the league's top passing team.
"We wanted to come out and establish the run game, and that's what we did," said Antolin, who had his best outing of the season.
Despite the win, Stoops was unhappy with inconsistent offensive play that allowed Washington State (1-6, 0-4) to remain within striking distance much of the game.
"We have to play better than we did tonight," Stoops said.
Arizona managed only 352 yards of offense and 24 points against a defense that was giving up more than 500 yards and 42 points per game. The Cougars recorded six sacks.
On the flip side, Washington State had just 297 offensive yards and failed to reach double digits in scoring for the first time this season.
"Missed opportunities and points left on the field," offensive lineman B.J. Guerra said.
"We've got to put it together," defensive end Travis Long added.
Foles was injured with 14:07 left in the second quarter when Long was tripped and rolled into his right leg, knocking him to the ground after a completed pass. Foles limped off the field, supported between two Arizona officials.
Scott completed 14 of 20 passes for 139 yards, but was intercepted once and sacked five times.
Washington State has lost 12 straight Pac-10 games dating to 2008, and has beaten only Montana State this season. But its passing attack continued to improve, with quarterback Jeff Tuel completing 18 of 32 passes for 257 yards, despite being sacked seven times. Freshman Marquess Wilson caught six passes for 131 yards.
Antolin scored on a 9-yard run late in the first for a 7-0 Arizona lead.
Foles had started the first eight plays of their second scoring drive when he was injured. Scott directed the team over the final 37 yards, with Antolin running up the middle from the 1-yard line for a 14-0 lead.
Arizona threatened in the closing minutes of the first half, moving 71 yards to the 19, but Scott was intercepted by Casey Locker in the final seconds to kill the drive.
Arizona's 14-0 lead was the first time this season that Washington State was shut out in the first half.
The Wildcats got a break early in the third when Washington State punter Reid Forrest fumbled the snap deep in his own territory. Khyri Knowles dove on the ball at the 7 and, on the first play, Grigsby ran in for a 21-0 lead.
Washington State got on the scoreboard when Tuel hit Wilson with a 23-yard touchdown strike late in the third.
But the Cougars blew a chance to tighten the game after they stopped Antolin on fourth-and-1 on the first play of the fourth quarter. Running back James Montgomery took a handoff and then threw a backward pass that was deflected by Arizona's Brooks Reed and recovered by D'Aundre Reed. Alex Zendejas eventually kicked a 40-yard field goal for a 24-7 lead.
Tuel connected with Wilson for an 83-yard gain midway through the fourth, giving the Cougars the ball on Arizona's 12 and Wilson the fourth 100-yard game of his rookie season. But Tuel was intercepted in the end zone to kill the threat.
The game was also costly for Washington State. The Cougars lost offensive lineman David Gonzales to a broken left arm and cornerback Damante Horton to a sprained knee.