HOUSTON -- What the heck is going on in Houston?

Playing for home-field advantage throughout the AFC playoffs, the 12-2 Texans are getting embarrassed 13-3 at the half in front of a crowd that's getting downright angry at their normally explosive offense.

Meanwhile, the Vikings are getting an unusually quiet game from Adrian Peterson (40 yards on 13 carries, including 20 on his last 12 carries), but an unusually exceptional day from quarterback Christian Ponder, who has completed 10 of 17 passes for 119 yards and a touchdown. He also ran 21 yards for a first down on third down.

Defensively, the Vikings have held Houston to 107 yards. And then there's Blair Walsh, who, of course, is kicking field goals that would be good from Dallas. And

The Texans took the opening kickoff and drove 46 yards in nine plays and took a 3-0 lead on a 51-yard field goal by Shayne Graham. The Texans' drive stalled when A.J. Jefferson reached in and broke up a pass to Andre Johnson. Chris Cook, who had been on injured reserve the previous six weeks, started the game but split time with Jefferson in the first half.

The Vikings took a 7-3 lead on their first possession. Peterson ran for 20 yards on the first play to extend his NFL-leading runs of 20 or more to 21. His next three carries netted zero yards, but Ponder carried the Vikings the rest of the way, completing 3 of 3 passes for 62 yards, including a 3-yard TD to Kyle Rudolph.

For those keeping tabs on the wildly inconsistent season that Ponder is having, here are the second-year QB's numbers on the first drives of the past two games: 6 for 6 for 100 yards, one touchdown rushing and one passing. One of his completions today was a 32-yarder to Michael Jenkins aganst a blitz on third-and-six.

The Vikings' defense set up the next score when Jasper Brinkley forced running back Arian Foster to fumble. Jefferson fell on it at the Vikings' 21-yard line.

Walsh capped the drive with his NFL record-setting ninth field goal of 50 yards or longer this season. This one tied Paul Edinger's team-record long of 56 yards. Walsh, a rookie, is 9 for 9 from 50 or longer. That broke the mark of eight held by Morten Andersen and Jason Hanson.

Walsh added a 41-yarder with 37 seconds left in the half. Walsh is 31 of 34 on the season.