"I really, really felt good tonight," Mulder said. "The one mistake, pretty much the only ball I left up in the zone, [Michael Barrett] hits for a homer. What are you gonna do? I just tried to get over it and throw up some more zeroes, especially with the lead we had."
The Cardinals (10-6) had lost four of their last five games against the Cubs (9-6) at the old Busch Stadium, and then lost three straight games at Chicago's Wrigley Field two weeks ago.
On Friday, it was Pujols (double, home run, four RBIs), Edmonds (two-run home run) and Mulder (three earned runs on five hits in eight innings) who made the difference.
Pujols hit a two-run home run in the first inning, the fourth straight at-bat the Cardinals first baseman had homered in at Busch after Sunday's three-home run game against the Reds. The home run, his Major League-leading 11th this season, was also the 1,000th hit of Pujols' career.
"Plus, it got us going in the game," Cardinals manager Tony La Russa said. "I'm sure he's happier about that."
The Cardinals broke the game open with five runs in the second inning.
Juan Encarnacion and Yadier Molina led off the inning with back-to-back singles, followed by consecutive walks by Aaron Miles and Mark Mulder. David Eckstein dropped an RBI single into shallow right, and John Rodriguez put the Cardinals ahead, 5-0, with a sacrifice fly to left field.
The next batter, Pujols, pounded a two-run double down the third-base line for his 23rd and 24th RBIs of the season and a 7-0 St. Louis advantage. That chased Cubs starter Jerome Williams (0-2) from the game.
"Mark was great today keeping the ball down," Pujols said. "We gave him some runs to support him. That's the key."
Mulder (2-0) struck out five batters and walked one. He threw 69 of his 97 pitches for strikes, and got 12 groundball outs. With his nemesis, Derrek Lee, sidelined with two broken bones in his wrist, the lefty befuddled the Cubs' lineup with his sinker.
"That's my game," Mulder said. "My game revolves around my sinker. I didn't have a good one my last start, and I had a better one tonight. When I have that, and I'm throwing strikes with it, in and out, obviously it opens up everything else for me."
Cubs catcher Barrett hit a three-run home run, his fourth on the year, off Mulder in the fourth inning. Those were the only runs Chicago was able to get off the lefty, who won for the second time in three starts.
"I think Dave [Duncan] said when he warmed up, that's about as good as he's seen him," La Russa said. "He took it into the game. Barrett swung at a sinker up and that's three runs, but he pitched very well."
Edmonds hit a two-run homer, his third of the year, off right-handed reliever David Aardsma in the fifth inning to give the Cardinals a 9-3 lead. It was the center fielder's second home run in two games and effectively dashed any momentum the Cubs had built from Barrett's homer.
Right-hander Braden Looper pitched a scoreless ninth to close out the game.