CHICAGO -- Many of the fans packing the stands at Wrigley Field on Wednesday were already on their feet when Nico Hoerner stepped up to hit in the eighth inning. And for anyone who was still seated, Hoerner did his part to get them on their feet.

Hoerner crushed his first career grand slam off Nationals reliever Cory Abbott, depositing a 93-mph fastball into the left-field bleachers that and sending the Friendly Confines into a frenzy to help push the Cubs to an 8-3 win and series victory over Washington.

“He needed that,” manager David Ross said. “That was a nice swing.”

It’s no secret Hoerner is as big of a key as anyone to the Cubs’ success offensively. But the 26-year-old has gone through some struggles in recent weeks.

Entering Wednesday, Hoerner held a .175/.235/.222 slash line through 14 games in July, with 17 strikeouts in 68 plate appearances (25 percent rate). However, that line includes a 3-for-6 showing in Tuesday’s win over the Nationals, perhaps an early sign that Hoerner is beginning to get on track.

“You really have no clue when he is struggling,” Cubs starter Kyle Hendricks said. “He’s such a hard worker and his at-bats don't change. Every at-bat is just a pro at bat. You think you have a chance of him getting a hit every time he's up there. 

“To come through like that in a huge moment, that's what he does for us. He’s one of the best players on our team and just super clutch. He just seems to get the hit when we need it.”

“Getting the barrel of the bat out front in an even count was really nice for him,” Ross added of Hoerner’s plate appearance in the eighth. “Just seeing the ball well, having confidence in himself out there. Not as jumpy tonight as he had been probably two or three nights ago.

“I feel like the timing is coming. Everybody feels like they’re starting to feel pretty good.”

The Cubs’ eight-run output came one night after they put up 17 against the Nationals, a full-team effort that included 14 runs in their final two innings at the plate, contributions coming up and down the lineup.

Before Wednesday’s game, Ross was asked generally how important one game can be for a player’s confidence, and the potential carryover effect of a big performance.

“Extremely,” the Cubs manager said. “The confidence of just getting three, four knocks in a game, or just that one knock that comes through of all the work you've been doing.

“There are these moments in the batting cage when you're doing your drill work and working on things or timing after games that, there's these ‘a-ha’ moments that just go, ‘Oh, that felt right. That feels like when I'm at my best.’”

Along with Hoerner, the Cubs got big offensive nights Wednesday from Seiya Suzuki (2-for-3) -- who’s gone through his own struggles in July -- and Mike Tauchman, who logged his first career game with three extra-base hits.

Tauchman started things off for the Cubs with a leadoff homer against Trevor Williams, added two doubles and drew a walk right before Hoerner’s slam.

“I feel like since he’s been here in the leadoff spot, that’s been our best version of our offense since maybe the first three weeks of the season,” Ross said of the 32-year-old outfielder. … “He’s done a really nice job for us. He’s a baseball guy and thinks the right things. He’s fun for that group and he’s been swinging the bat really well, getting on base, doing a nice job at the top.”

Before the late rally, Hendricks spun his sixth quality start this season with six innings of five-hit, one-run ball. It was a vintage performance for the right-hander, who has thrown six quality starts in 11 outings this season.

It was an important night for the Cubs, who are in a manageable stretch on their schedule with the Trade Deadline only two weeks away.

Right now, they’re taking things day by day and focused on sustaining the momentum they’ve built the last two days. That continues Thursday, when they will welcome the rival Cardinals to Wrigley for a four-game series.

“That’s where our focus has been,” Hendricks said of keeping the momentum. “That sense of urgency, just winning each day.”

Said Ross: “We’ve got a big series ahead of us with the Cardinals coming in, four games against them. See if we can carry a little bit of momentum into that series.”