Juan Yepez lined a one-out double to the left field wall off Cubs reliever Mark Leiter Jr. (1-2) in the eighth, and pinch-runner Edmundo Sosa advanced to third on a wild pitch before scoring the go-ahead run on Herrera’s fly.
“Sosa has been like my brother here,” said Herrera, a rookie catcher vying to replace Yadier Molina when he retires. “He's helping me a lot trying to understand how to handle things. I know I did something different, and he said focus now because you're going to get an important at bat to help the team win.”
Harrison Bader advanced to second on Herrera’s out and scored on Tommy Edman’s single to right field to extend the lead to 5-3.
Ryan Helsley (3-0) pitched 1 2/3 scoreless innings to lower his ERA to 0.31.
Miles Mikolas allowed one run on four hits while matching his season high of nine strikeouts. His 2.06 career ERA in 13 games (11 starts) against the Cubs leads all active pitchers with at least 10 starts.
“He's thrown really well,” Cardinals manager Oliver Marmol said. “He got after it, attacked with the fastball, dominated with the fastball, and between that and the curveball, nine strikeouts. He did a really nice job.”
Mikolas is 1-2 in his last 4 starts despite posting a 1.55 ERA and allowing 12 hits in 29 innings.
“Teams have up and downs,” Mikolas said. “Offenses have ups and downs. Pitchers have ups and downs. I'd like to have more wins. I may only have one, but we won today and that's a win in my book."
Adrian Sampson allowed two runs when St. Louis strung together a trio of two-out hits in the first inning, but he gave up just one additional hit in his five innings of work.
“The two runs he gave up were soft contact, just found some outfield grass,” Cubs manager David Ross said about Sampson. “I thought he threw the ball really well, got a nice rhythm there, kept those guys off balance, a really nice performance.”
“He's done nothing but have quality at bats,” Ross said. “A big home run right there to tie it up for us. He's going to be locked in whenever he gets a chance.
Goldschmidt went 2 for 4 to boost his major league-leading home batting average to .395.
Cubs: RHP Marcus Stroman (right shoulder inflammation) threw approximately 40 pitches in a pregame bullpen session. He could throw a live batting practice session when the Cubs return home Tuesday.
Cardinals: LHP Génesis Cabrera was placed on the injured list with no designation. The club recalled RHP Jake Woodford from Triple-A Memphis.
The Cubs and Cardinals wrap up their three-game series Sunday as RHP Alec Mills (0-1, 8.59 ERA) will make his first start of the season after pitching in five games out of the bullpen. He is 0-2 with a 4.26 ERA in seven career outings against St. Louis. RHP Jack Flaherty (0-0, 7.50 ERA) will make his third start after opening the season on the injured list with right shoulder inflammation.
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