LITTLE ROCK, Ark. (AP) — With its top running back out for the season, Arkansas relied on Ryan Mallett’s arm against Mississippi State.

As usual, the sophomore was up to the challenge.

Mallett threw for 313 yards and five touchdowns to lead the Razorbacks to a 42-21 victory on Saturday, hours after the team announced running back Michael Smith would miss the rest of the year with a hamstring injury. Mallett’s second pass of the game was intercepted, but Arkansas took the lead in the second quarter and didn’t relinquish it.

“They were committed to stopping the run,” Arkansas coach Bobby Petrino said. “Part of me wishes I could’ve thrown it every down, but that’s hard to do.”

Mallett’s final touchdown pass was his 28th of the season, a school record. Clint Stoerner held the old mark of 26.

Anthony Dixon rushed for 176 yards for Mississippi State, which was eliminated from bowl contention.

The Bulldogs (4-7, 2-5 Southeastern Conference) ran all over the Razorbacks (7-4, 3-4) in the third quarter, cutting the Arkansas lead to 28-21 after Dixon’s 70-yard scoring run. Mississippi State had the ball near midfield toward the end of the period, but Dixon fumbled and Elton Ford recovered for the Razorbacks.

“I think we started to run the ball downhill a little more in the second half,” Dixon said. “I took the handoff and before I could turn right, the Arkansas defender was under me, knocking the ball loose.”

Mallett threw an 11-yard touchdown pass — off his back foot while scrambling from pressure — to Greg Childs to make it 35-21 early in the fourth. He finished 18 of 34 with two interceptions.

“I thought the offense and defense did a good job of looking out for one another. When one wasn’t getting the job done, the other stepped up and made some big plays. We played well as a team,” Mallett said. “You’re going to throw picks every now and then. You just have to bounce back.”

Smith rushed for 1,000 yards last season, but he fought injuries throughout 2009. His absence should mean more opportunities for Broderick Green, Dennis Johnson and Ronnie Wingo Jr. in the backfield.

“With Mike out, that’s a key part of the running game,” wide receiver Joe Adams said. “We’ve got other backs that have got to step up.”

On Saturday, the other running backs struggled a bit, as the Razorbacks were outrushed 327-83. That didn’t matter by the time Mallett was done. He’s the only Arkansas player to throw for five touchdowns in a game, and this was the third time he’d done it this year.

Mallett, who normally downplays his stats, acknowledged he realized he’d tied that record.

Arkansas began the game on a sour note when Mallett was intercepted on his second pass. Mississippi State mishandled its first snap, but wide receiver Chad Bumphis picked up the ball in the backfield and ran all the way to the Arkansas 3 for a 49-yard gain. Arnil Stallworth’s 1-yard touchdown run made it 7-0.

The Razorbacks answered with Mallett’s 39-yard touchdown pass to Adams, then took the lead on his 58-yard scoring toss to Cobi Hamilton in the second quarter.

Mallett’s 5-yard touchdown pass to Jarius Wright gave the Razorbacks a 21-7 halftime lead.

Dixon’s 4-yard scoring run pulled Mississippi State to within seven early in the second half, but Mallett answered with a 64-yard strike to Hamilton.

The third-and-long play started as a simple screen, but Hamilton eluded two tacklers and outran the defense for a touchdown and a 28-14 advantage.

“Five touchdown passes is a heck of a day,” Mississippi State coach Dan Mullen said. “Our secondary didn’t make plays that were there to be made.”