DeMarco Murray exploded for 175 yards and a touchdown on 26 carries, while Tony Romo threw for three scores, as Dallas pounded St. Louis, 31-7, in Week 3 action.
"When you get a runner like that going, you can feed on him," Cowboys head coach Jason Garrett said. "He gets a little contagious for everybody. Everybody starts feeling it."
Romo finished at 17-of-24 efficiency for 210 yards for the Cowboys (2-1), who bounced back from a one-point loss in Kansas City last week.
Dez Bryant, Gavin Escobar and Dwayne Harris all posted a receiving TD, with Jason Witten leading the pack with 67 yards on five catches.
Sam Bradford ended up with 240 yards passing and a score to Austin Pettis on 29-of-48 completions for the Rams (1-2), who have dropped two in a row.
"In the first half, we just never got anything going, played behind the chains all day," Bradford said. "Just a very poor performance on our part today."
Bryant capped Dallas' second drive of the contest with a diving grab in the back left corner of the end zone for a 2-yard touchdown.
After holding St. Louis to a three-and-out, Murray's 36-yard dash down the right side to the Rams' 23-yard line on first down helped set up Dan Bailey's 19-yard make for a 10-0 lead late in the opening quarter.
It was 17-0 for the hosts after replay upheld Murray's 2-yard run to the near pylon on the left side. The score ended a 67-yard, 10-play series which began at the outset of the second period.
"I don't know that there was anything that stood out to me, other than it was just the same commitment and drive and work ethic he's shown all year in the offseason and the first two games," Romo said in praise of his running back.
Murray broke free for a 41-yard run on the second play of the Cowboys' first series of the second half. It brought Dallas to the Rams' 33, and four plays later, a 24-yard Romo-to-Escobar connection made it a 24-point spread for the hosts.
St. Louis managed to reach field-goal territory on the next possession. Bradford's pass over the middle on 4th-and-5 was picked off by J.J. Wilcox, but his return -- which would have given the Cowboys possession on their own 30 -- was nullified by a roughing-the-passer call. The Rams took over on the Dallas 15, and Pettis later hauled in a 4-yard TD pass on a slant pattern.
Bradford's incompletion on a 4th-and-4 from his own 45 early in the fourth gave the ball back to the hosts, who needed only three plays to take a 31-7 lead after Romo threaded the needle to Harris for a 24-yard touchdown pass.
"We didn't run, we didn't stop the run, we didn't throw, we didn't stop their passing game," Rams coach Jeff Fisher lamented. "I did not see this coming."
Dallas improved to 4-2 vs. the Rams since the franchise's 1995 move to St. Louis ... Cowboys DE DeMarcus Ware recorded a pair of sacks, giving him 114 for his career and eclipsing the previous Dallas record held by Harvey Martin ... Bryant finished with 38 yards on four receptions and Murray added 28 yards on three grabs ... St. Louis was held to 232 yards of total offense, including just 18 total in the first half ... Cowboys wideout Miles Austin left the game with a hamstring issue and didn't return.