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 Peterson made an interception in the back of the end zone.
Arizona's loss leaves Atlanta and Houston as the only 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 after starting the 2011 season 1-6.
NOTES: Fitzgerald broke the mark set by Mel Gray from 1973-82 and finished with eight catches for 92 yards, leaving him 48 yards shy of 10,000 for his career. ... Kurt Warner, who took the Rams to two Super Bowls and the Cardinals to one, got a huge sustained ovation when he was introduced in the first quarter. Warner and another former Rams great, Marshall Faulk, are on the NFL Network broadcast team. ... Rams S Quintin Mikell and Cardinals backup LB Reggie Walker were sidelined by blows to the head.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.