"Like when I watch my friends do something, I'm always more nervous than when I do it," Wainwright said.
"When I watch my daughters, even at ballet or something, I'm more nervous than if I was out there doing ballet."
Allen Craig's game-ending leaping catch high at the left field fence preserved a 3-2 victory against the San Diego Padres on Sunday.
Wainwright became the first NL pitcher to reach 13 wins.
The Cardinals have won nine of 12. The Padres have lost 19 of 24.
Craig has 12 hits and six RBI during a seven-game hitting streak for the Cardinals, who took two of three in both series against the Padres this season.
He's a confident defender, too, and never thought pinch hitter Jedd Gyorko's drive with two on and two outs was going out of the park.
The glove work prevented at least an extra-base hit that would have given the Padres the lead, and preserved Edward Mujica's 28th save in 30 chances.
"Obviously, it came off the bat good," Craig said. "I don't know if he hit it good enough. Obviously, it wasn't enough."
Gyorko agreed with Wainwright's assessment that he just got under the ball a little. He hadn't viewed a replay, and didn't want to, either.
"No. It was a good play," Gyorko said. "That's how the game goes sometimes."
The St. Louis defense turned three double plays behind Wainwright (13-5), who allowed two runs with seven strikeouts and worked around two walks. The Padres got the leadoff man on base seven times but he minimized the impact.
"He got tough with guys on base, no doubt about it," Padres manager Bud Black said. "He's a veteran pitcher with a lot of know-how.
"We had good swings against an All-Star pitcher. To a man, we fought him. He knew it."
Yonder Alonso singled three times with an RBI for the Padres. Eric Stults (8-8) allowed three runs and eight hits in six innings, stranding two runners in the second and fifth, falling short in a bid to win three consecutive starts for the first time in his career.
"This is a team where they get guys on base and they get in kind of a swing mode, they want to score quick," Stults said. "That third inning got away a little bit."
Wainwright matched his season high for walks after entering with a NL-low 15 in 146 2/3 innings. He had only one perfect inning but got key outs with breaking balls and struck out Everth Cabrera with a man on third to end the seventh.
Wainwright is 5-2 with a 1.47 ERA against the Padres after beating them for the second time this season.
Freese was thrown out at third on strong relays from right fielder Will Venable and Cabrera and the Cardinals had just one more runner in scoring position the rest of the way.
Matt Carpenter opened the third with a double off the base of the wall in right-center for his second successive hit and leads the majors with 39 multi-hit games.
Cabrera led off the game with an opposite-field double, a chopper down the third-base line that Wainwright called a "doink fest," and scored on Alonso's two-out hit.
The Padres cut the deficit to a run in the sixth on a double by Carlos Quentin, another Alonso hit and a double-play ball.
- Thousands lined up outside Busch Stadium several hours before game time for Stan Musial replica statues and a near-sellout of 44,033 was the Cardinals' 14th straight of 43,000 or more.
- Carlos Beltran got a day off due to general soreness, although he told manager Mike Matheny he could play.
- The Cardinals have a day off before rookie Shelby Miller (9-6, 2.92) makes his first start after a 12-day break against the Phillies Tuesday. Andrew Cashner (5-5, 3.81) pitches for San Diego in the opener of a four-game set in Milwaukee.
- Padres OFs made a pair of outstanding plays. Venable's sliding catch left a long skid mark in foul territory in the fourth and LF Quentin snatched Craig's liner to end the seventh.
- Stults threw a career-high 124 pitches.