Wainwright was a 14-game winner coming off reconstructive elbow surgery that sidelined him all of 2011, with 10 of the wins coming at home. He's been a postseason ace with a microscopic 0.77 ERA and 32 strikeouts in 23 1-3 innings.
He fanned Bryce Harper and Ryan Zimmerman twice each and seventh-place hitter Espinosa all three times.
"His breaking ball really bailed him out today and kept them off-balance and had a lot of swing-and-misses and some chases and strikeouts with the breaking ball," Cardinals manager Mike Matheny said.
Gonzalez allowed just one hit in five innings, on David Freese's full-count bouncer between third and short to start the fourth. But he had trouble finding catcher Kurt Suzuki's glove.
The second inning was Gonzalez' shakiest when he allowed the Cardinals to score twice and take the lead without a hit. Gonzalez walked four of the first five hitters, putting St. Louis in position to score one run on a wild pitch and a second on Jon Jay's bases-loaded sacrifice fly.
Nationals right fielder Jayson Werth robbed Daniel Descalso of a two-run homer off with a leaping catch to keep it at 2-1 in the sixth. Descalso had a fielding gem of his own in the seventh, ranging far to his left to glove Harper's grounder and then throwing him out by a few steps.
Both pitchers were aided by the late-afternoon shadows. The narrow roof above the top of the upper deck, and lattice work beneath the roof, creates a hodge-podge of sun and shade. At one point, pitchers were throwing from sunshine into shade, a small stretch of sun then shade again.
It was little surprise there were just five singles and no runs in innings three through six, when the shadows were most prominent.
"He's hard to hit when you can see well, and even harder when you can't," Holliday said of Gonzalez. "It's hard to hit when you can't see the ball, see the spin on the ball."
NOTES: The Cardinals went 0 for 8 with runners in scoring position. ... Garcia was 4-2 with a 2.82 ERA in nine starts at home. The lefty has a 2.48 career ERA at Busch. ... Kozma committed one error in 26 games after taking over as the regular SS in September for injured Rafael Furcal.