Center fielder Jon Jay made a sliding catch on Placido Polanco's soft fly for the final out, and was already pointing his index finger before he got to his feet.
Now it's back to Philadelphia for Game 5 on Friday night. Roy Halladay, who won the opener for the Phillies, will face St. Louis ace Chris Carpenter. Cardinals manager Tony La Russa has already called it a dream matchup.
The 102-win Phillies are favored to win it all. But first they must dispose of the wild-card Cardinals, who clinched a playoff spot on the last day of the season and have gotten the best of two members of the Phils' star-studded rotation.
And suddenly, this first-round series has gotten squirrelly for the Phillies. An omen, maybe: Right after Oswalt threw a pitch in the fifth, a squirrel darted across the plate.
Albert Pujols was hitless in four at-bats in what could have been his final home game with the Cardinals. He received thunderous cheers every trip to the plate from a standing room crowd of 47,071, second-largest at 6-year-old Busch Stadium.
Pujols made his presence known on defense, catching Chase Utley going for an extra base in the sixth. Utley drew a leadoff walk and kept running on Hunter Pence's grounder to short, but Pujols alertly jumped off first base to catch the throw and made a sharp relay to third for the out.
Edwin Jackson recovered from a rocky beginning to win his first playoff start. After giving up two runs on his first five pitches, he wound up throwing six solid innings. Jason Motte worked a perfect ninth for his second save of the series.
Phillies cleanup hitter Ryan Howard was 0 for 4 with three strikeouts. He is 0 for 8 the last two games with five strikeouts and has hit only one ball out of the infield.
Oswalt had been 5-0 with a 3.25 ERA in 10 previous postseason starts, the biggest closing out old Busch Stadium and the Cardinals in 2005 to get Houston to its first World Series. The right-hander also worked seven shutout innings against St. Louis in the Phillies' NL East division clincher in mid-September.
The biggest jolts for the Cardinals came from their seventh-place hitter. Freese was 2 for 12 the first three games with one RBI before punishing the fourth of the Phillies' aces.
Freese's two-run double down the third-base line in the fourth put St. Louis up 3-2. His two-run homer to straightaway center in the sixth whipped the crowd into a towel-waving frenzy.
Oswalt walked Lance Berkman and hit Matt Holliday, making his first start of the series, to start the fourth. Right fielder Hunter Pence made a fine running catch at the warning track to rob Yadier Molina of extra bases, but Freese jumped on a hanging curveball with a drive down the left-field line.
Holliday singled with one out in the sixth and Freese hit a 1-0 pitch to the pasture in straightaway center, not far from where a squirrel made an early appearance, for a three-run cushion. A squirrel also interrupted play in the fifth, racing across the plate an instant after Oswalt's pitch to Skip Schumaker passed for a ball.
Oswalt argued with home plate umpire Angel Hernandez, asking for no pitch. Phillies manager Charlie Manuel also argued without success and Schumaker, flied out to center on the next pitch.
In Game 3 Tuesday, a squirrel was seen scampering in foul territory along the third base line.
Five pitches into the game, the Phillies had a 2-0 lead with an assist from the late-afternoon playing conditions.
Jay, standing in bright sunshine while shadows, took one step in on leadoff man Jimmy Rollins' drive on the first pitch of the game and retreated too late for a ball just over his glove that bounced over the wall for a ground-rule double.
Utley tripled just inside the first-base line three pitches later and Pence lined an RBI single on the next pitch.
NOTES: 2B Schumaker was taken out with a left hamstring cramp after a flyout in the fifth - the same at-bat the squirrel made its appearance. After disrupting play, the squirrel scampered through the stands. Schumaker is 5 for 8 in the series. ... Rollins doubled and had an infield hit his first two trips and has nine hits in the series. He has 14 multihit games in the playoffs, passing Howard for most in franchise history.