ST. LOUIS (AP) — Even before Sam Bradford snapped out of it, the St. Louis Rams had enough points.

Their fast-improving defense saw to that.

Bradford busted a lengthy slump 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 previously unbeaten Arizona Cardinals in check in a 17-3 victory Thursday night.

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 on the year, and 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 Seattle, also at home.

Lance 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.

Bradford had been 3 for 16 for 25 yards and an end-zone interception since the opening drive, often missing on his receivers by a lot. Undoubtedly, he missed Danny Amendola, sidelined in the second quarter with a right shoulder injury on a diving attempt that was initially ruled a 22-yard catch for a first down but overturned after the Cardinals challenged.

Amendola perhaps hinted at the extent of the injury when he flung his helmet, with his left hand, while walking in a tunnel to get X-Rays.

The Rams, ranked 27th in offense, came out throwing, with Bradford completing passes of 14 yards to Brandon Gibson and 44 yards to Amendola on the first two plays, setting up the score to Kendricks on third down. It was the first offensive touchdown in three games for St. Louis.

Arizona responded with a drive that lasted 9:24, ending with Jay Feely’s 35-yard field goal. The Cardinals kept the drive alive with three third-down conversions. Larry Fitzgerald’s 5-yard catch on the first play of the drive marked the 122nd straight game with a catch, a franchise record.

Zuerlein, a sixth-round draft pick out of Missouri Western, made it 10-3 early in the second quarter. He is 13 for 13 this season, including four kicks of 50-plus yards.

Feely missed a 40-yard field goal late in the second quarter.

Bradford was 3 for 4 for 65 yards on the opening drive before cooling off. St. Louis was well within Zuerlein’s range at the Arizona 16 late in the third quarter when a pass was intercepted by Patrick Peterson in the back of the end zone.

Arizona’s loss leaves Atlanta and Houston as the only remaining unbeaten teams. The Cardinals were still the St. Louis Cardinals the last time they were 4-0, in 1974. Known as the “Big Red,” those Cardinals won their first seven that season en route to a 10-4 record, before losing in the first round of the playoffs to Minnesota.

The loss was only the Cardinals’ third in 14 games since starting the 2011 season 1-6.