With Kurt Warner at the helm, Arizona looked like a team primed to make a deep run in the playoffs as they built a 21-3 halftime lead without breaking a sweat . With Matt Leinart under center after Warner was knocked out of the game just before halftime, the Cardinals couldn’t produce much of anything on offense the rest of the game, but held on anyway thanks to another strong showing from both their defense and their running game to win 21-13.

The injury to Warner is not expected to be serious, and he may have even been able to return in a more competitive game. Instead, coach Whisenhunt used it as an opportunity to get Leinart some reps against an opponent that wasn’t posing a serious threat. While it is always good to get the backup quarterback some playing time, Leinart’s play was uninspiring. Despite completing 10 of his 14 passes he opted for the check down pass to backs or ends more often than not. Four of the six drives under his command ended in punts, and none of them ended with points.

The game started on a bad note, as Beanie Wells fumbled on a pitch out on the third offensive play of the game to give the Rams the ball at the Cardinals’ 25 yards line, which ended in a field goal for St. Louis four plays later. It was all Cardinals though for the rest of the half.

Warner completed 15 of his 19 passes for 203 yards and 2 TDs, and the running game continued its hot streak. While most of the chatter has been about rookie sensation Beanie Wells’, Tim Hightower again demonstrated the skills that are keeping him entrenched as the starter. Hightower broke off a 50-yard run, the longest of his career and the longest for an Arizona back since 2004, and ended the day with 110 yards on 14 carries. Wells ran strong and showed off his trademark devastating stiff arm to the tune of 74 yards and a TD on 14 carries of his own.

Larry Fitzgerald and Anquan Boldin had their usual solid outings, with 8 catches and a TD each, while Steve Breaston was surprisingly held without a catch. Ben Patrick and Early Doucet got in the action with two critical catches. Perhaps no play was more important than Doucet’s 20-yard grab on a 3rd and 4 at the Arizona 13 with 2:35 remaining in the game, which was also happened to be Leinart’s lone highlight of the day as he narrowly missed taking a sack on the completion.

The defense took a hit when starting CB Bryant McFadden left the game with an injury, but stood firm and harassed the Rams most of the day. Although Steve Jackson’s stats say he gained 116 yards, truth be told the Cardinals held him in check save for one lone play—his 48-yard scamper—and that was the key to having control of the game. Arizona registered 3 sacks and an interception, and overwhelmed a weak St. Louis offense at the point of attack.

Had Warner not been forced from the contest, this game had blow out written all over it. The scary part for Arizona fans is seeing what their team is incapable of without Kurt in the lineup. With Warner this team could make it back to the Super Bowl, but if he is injured for any length of time, Leinart has not proven to be effective in his stead.

While this win was far from pretty, it elevated the Cardinals to a 7-3 mark for the second year in a row, and with both the 49ers and Seahawks losing once more the division title is the Cardinals’ to lose barring a colossal collapse. Or a Warner injury.