ST. LOUIS (Interstat) — Kyle Leahy pitched 5 1/3 innings of one-run ball, Iván Herrera drove in three runs and the St. Louis Cardinals defeated the Milwaukee Brewers 6-3 on Monday night at Busch Stadium III.

Leahy (4-3) struck out five and walked two while scattering six hits. Riley O’Brien recorded the final two outs in the ninth inning for his 10th save of the season. The Cardinals improved to 21-14, while the Brewers dropped to 18-16.

The game turned in the fourth inning after St. Louis broke a 1-1 tie with a three-run outburst. With the bases loaded and two outs, Herrera ripped a double to center field that cleared the bases, giving the Cardinals a 4-1 lead. The inning began with a double by Nathan Church, a walk to Pedro Pagés and a sacrifice bunt. Milwaukee starter Chad Patrick intentionally walked JJ Wetherholt to load the bases before Herrera delivered the decisive blow.

Milwaukee had taken an early 1-0 lead in the first inning on a double by Jackson Chourio, who later scored on a groundout. The Cardinals tied the game in the second when Wetherholt singled home Masyn Winn, who had walked and moved to third on a single by Victor Scott II.

Brewers starter Chad Patrick (2-2) allowed four runs on six hits over 3 2/3 innings. He walked three and struck out four. Milwaukee’s bullpen fared better, with DL Hall tossing 1 2/3 scoreless innings and Shane Drohan working 1 1/3 innings, but the damage was done.

The Cardinals added an insurance run in the seventh. Jordan Walker walked and took second on a groundout by Nolan Gorman. Masyn Winn singled to right field, scoring Walker and sending Gorman to third, though Gorman was thrown out at third on the play.

St. Louis extended its lead to 6-1 in the eighth inning. Victor Scott II doubled and scored on a single by Wetherholt.

Milwaukee mounted a late rally in the ninth inning. Jackson Chourio led off with a double, and Brice Turang followed with a two-run home run to center field, his fifth of the season, cutting the deficit to 6-3. William Contreras then singled, but Ryne Stanek relieved for St. Louis and got a forceout and a flyout to end the game.

Chourio finished 4 for 4 with two doubles and a walk, raising his average significantly. Turang went 3 for 5 with the home run and two RBIs. For St. Louis, Herrera was 2 for 5 with three RBIs, and Wetherholt went 2 for 4 with two RBIs.

Milwaukee had 11 hits and left nine runners on base. St. Louis also had 11 hits and stranded five. The game lasted 2 hours, 48 minutes in front of an announced crowd of 22,080.

Interstat’s game simulator projected a final score of St. Louis 6, Milwaukee 4. Interstat’s ELO system gave the Brewers a 56.90 percent probability to win. Milwaukee entered as a pregame favorite with a spread of minus 1.5. The total runs of nine went under the over-under line of eight.