CHICAGO -- When the Cubs' lineup is clicking on all cylinders, it can force a lot of pitching staffs to have a long day.

On a hot day at Wrigley Field, it wasn’t the sun that did in Pirates starter Jordan Lyles, but the Cubs’ offense -- which was just as hot in jumping all over Lyles for seven runs in the first inning.

While the seven runs jump off the page, the Cubs approach during their breakout inning should stand out just as much.

Prior to the 10-4 victory on Saturday afternoon, Cubs manager Joe Maddon spoke about his team’s need to force pitchers to get out of the zone and work more walks, if need be.

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“They hear me say it all the time,” Maddon said. “I really believe that our success lies within our concept right there.”

Specifically, outfielder and newly anointed leadoff man Kyle Schwarber, who is known as a high-on-base percentage guy (.355 OBP in 2018), but came into Saturday’s game with an OBP of just .315.

The Cubs worked four walks during the first inning and six in the game, scoring four runs off the free passes. Schwarber worked two of the four walks, setting the table for the team’s monster offensive performance.

“Letting it come, not forcing it, just looking for a walk,” Schwarber said. “The first inning there, I get to 3-0 and he throws a strike. I just told myself, ‘Take another one,’ and if he throws a strike, it’s probably going to be another heater. He throws a strike on 3-2 and then walks me. I get on base, Kris walks and then it all kind of goes from there.”

It did go from there and in a big way, too, as the Cubs would send 11 men to the plate following the Schwarber free pass, scoring seven runs on five hits, including a three-run blast from catcher Willson Contreras. The Cubs’ offense scored 10-plus runs for the 11th time this season.

“We worked better at-bats all day. Accepted our walks. Moved it along to the next guy,” Maddon said. “It was hot out there. We we’re ready to play.”

The seven-run first inning came in support of starter Jon Lester, who did what he usually does when he’s on the mound. He gave Chicago a quality start, tossing 6 2/3 innings and allowing just three runs, with six strikeouts against no walks. Lester is 4-1 with a 2.97 ERA in his last five starts.

But it was his work at the plate that stood out on Saturday.

“Jonny Lester can swing the bat,” Maddon said with a chuckle. “It’s not a surprise."

Not known for his hitting prowess, the Cubs’ ace finished the game 2-for-3 with his first homer of the season, two runs scored and three RBIs.

“Obviously, over here [in the National League] it’s a little bit more important,” Lester said. “Like I’ve said before, I take a little bit more pride in my at-bats since I’ve been over here. Just try to give quality at-bats. I was able to square two of them up today.”