CHICAGO (AP) — When the St. Louis Cardinals arrived at Wrigley Field for a three-game series, manager Mike Matheny shook off questions about their 12 1/2-game deficit to the surging Cubs by insisting he avoids looking at the standings.

“It’s just not allowing me to fall into the trap, the trap of either being content or being overwhelmed,” Matheny said.

Three games later, Cardinals showed the NL Central may not be sewn up just yet.

Michael Wacha pitched into the seventh inning for his first win in nearly two months and the Cardinals waited out Jake Arrieta before roughing up Chicago’s bullpen in a 7-2 victory over the Cubs on Wednesday.

Aledmys Diaz hit a two-run home run, and Matt Carpenter had a two-run double in a five-run sixth after Arrieta (11-2) departed. The Cardinals won their eighth straight road game — their longest streak since 1982 — and completed their first three-game sweep at Wrigley Field since 1988.

“This is a big series for us,” Carpenter said.

Arrieta was charged with two runs — one earned — and four hits in five innings as he struggled with control (four walks) and pitch count (106).

“Go back to work tomorrow and combat the things that teams have done against me recently,” Arrieta said.

Wacha (3-7) allowed two hits until rookie Willson Contreras’ one-out, two-run homer in the seventh ended his day.

Contreras replaced Miguel Montero an inning earlier after the catcher twisted his right knee. He said after the game he was fine.

The Cubs had three hits and committed several mental and defensive miscues. Their three-game skid matches the longest of the season.

“Give them credit. They pitched well, they really played well and they beat us fair and square,” manager Joe Maddon said.

Chicago entered the series the darlings of baseball. But the Cardinals, who won 100 games last season before falling to the Cubs in the playoffs, showed their mettle.

Wacha set down the first nine batters before giving up two walks in the fourth and then Anthony Rizzo’s opposite-field single against the shift with two out.

But the Cubs didn’t score thanks to Chris Coghlan getting doubled off first base on a fly to left, and Wacha was able to snap a seven-game skid.

“It’s been a while for sure,” Wacha said.

The Cardinals made Arrieta work with long at-bats before taking advantage of Chicago’s shoddy defense.

“We grinded 1 through 9, even Wacha had a pretty long at-bat (seven pitches) against him,” Carpenter said. “We worked his pitch count and had runners on base. The error, that ended up being the difference in the game.”

A single and two walks loaded the bases in the fifth with one out when Stephen Picotty hit a grounder to third. But second baseman Ben Zobrist’s relay throw to first was a one-hopper, Rizzo couldn’t dig it out for the double play, and two runs scored.

“That was a big moment there,” Rizzo said. “I just missed it.”

Justin Grimm replaced Arrieta and was charged with four runs while getting one out in a nightmare sixth for Chicago before Contreras hit his second big league homer.

Rizzo later left the game as a precaution with a tight back.

“If it wasn’t 7-0, I think I would have stayed in the game,” Rizzo said.