ST. LOUIS — Sam Bradford missed high, low, left, right.

After capping the St. Louis Rams' opening drive with a touchdown pass to Lance Kendricks, the former No. 1 overall pick endured an 0-for-12 slump that included Patrick Peterson's interception in the end zone on a pass tossed up for grabs under heavy pressure.

No worries. The Rams' rapidly improving defense saw to that.

"Those guys played outstanding," Bradford said after the Rams knocked off the previously unbeaten Arizona Cardinals 17-3 on Thursday night. "They've played great all year, and they have kept us in a lot of games."

Bradford busted out of his funk with a 52-yard touchdown pass to rookie Chris Givens for a two-TD cushion and Robert Quinn had three of the Rams' nine sacks on Kevin Kolb to keep the Cardinals in check.

The Rams have three first-round picks on the defensive line and the fourth, tackle Kendall Langford, was a key free-agent pickup.

"We believe in ourselves," Quinn said. "We believe we can be one of the great defenses. When there was a play to be made, we made it."

Arizona (4-1) scored at least 20 points in each of its first four games, but had no luck containing a pass rush that had totaled just six sacks for the year. Arizona got stopped twice inside the 20 in the final minutes. The Rams also had a strong defensive game last week in a 19-13 victory over the Seahawks, also at home.

Kolb got his helmet knocked off twice on hits, once after getting popped in the jaw. He described the Cardinals' first-half woes as "sickening."

"I'm all right," Kolb said. "I'm glad we've got the weekend to heal up, mentally and physically."

The Rams also limited the Cardinals to 45 yards rushing.

"Bottom line, they decided they wanted to throw the ball a lot and that made it kind of a track meet," Rams defensive end Chris Long said. "We've been waiting a long time to feel like we've done our job on defense."

Kendricks caught a 7-yard TD pass in the first quarter and Greg Zuerlein kicked a 53-yard field goal in the second quarter for the Rams (3-2), who are 3-0 at home and ended Arizona's seven-game winning streak in St. Louis — the Cardinals' home before leaving for the desert in 1988.

The Rams totaled two victories last year but so far have executed a quick turnaround under new coach Jeff Fisher. They're 3-0 at home for the first time since 2003, when they were unbeaten in the Edward Jones Dome and they're above .500 for the first time since they were 4-3 on Nov. 4, 2006.

"I've never been there before," Long said. "I'm unfamiliar with the sound of it, but I'm liking it."

Bradford finished 7 for 21 for 141 yards.

Notes

• Carolina Panthers coach Ron Rivera said he's considering moving first-round draft pick Luke Kuechly to middle linebacker Sunday against Seattle if Jon Beason (knee) is unable to play.

• New York Jets tight end Dustin Keller (hamstring) and rookie wide receiver Stephen Hill (hamstring) were among six players who sat out practice with injuries as the team prepares to play undefeated Houston on Monday night.

• Green Bay Packers wide receiver Greg Jennings (groin) will not play Sunday at Indianapolis.