CHICAGO -- When Nick Pratto stepped to the plate Friday night against the Padres, he was mired in an 0-for-21 slump. He had not had a hit in nearly two weeks, since Aug. 13.

In the four games since, including Friday, the rookie first baseman is 8-for-17 with four doubles, three home runs and 10 RBIs.

The best game yet of Pratto’s young career came Tuesday night at Guaranteed Rate Field, when he went 4-for-5 with two home runs and a double, notching his first MLB multi-homer game and first four-hit game.

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That sparked the Royals to a 9-7 win over the White Sox. Kansas City scored in every inning except the first and ninth to offset both Brady Singer, who allowed four runs in 4 2/3 innings, and Scott Barlow, who allowed a two-run homer in the ninth, getting hit around.

“It’s definitely a feeling of confidence, knowing that I can trust the work I’ve done and trust the homework and everything,” said Pratto, ranked by MLB Pipeline as the Royals' No. 2 prospect. “Continuing to do that and dominating my process before the game.”

Pratto’s process has been key to his surge, even throughout his slump. That’s what’s been most encouraging for the Royals to see from the 23-year-old.

“He had a plan on what he was trying to do, what he was seeing each day that wasn’t working and what he needed to do to make an adjustment,” manager Mike Matheny said. “If he can continue to do that and stay in that positive state of mind when things start heading in a tough direction … I think it leads you to being able to have a night like tonight.”

Pratto’s second home run of the game set a new franchise record for rookie home runs in a season with 57. His first home run tied the 1969 club’s 56 rookie home runs.

There have been 18 MLB rookies with multi-homer games this year, and the Royals have three of them: Pratto, MJ Melendez and Bobby Witt Jr. It’s the first time in club history three different rookies have had two-homer games in the same season.

“They got some pop,” Singer said. “We’ve talked about these guys the whole entire year. How much fun it is having a bunch of young guys in here, bringing us life.”

Pratto was the only rookie to homer Tuesday, but he wasn’t the only Royal. Salvador Perez -- who was also a triple away from the cycle -- hit his team-leading 19th blast of the season in the third inning, and Michael A. Taylor joined the party in the eighth with his eighth of the year during a three-RBI night for the center fielder.

“If I get a homer like that, I’m not going to be afraid to swing at any pitch,” Perez said. “I’m super aggressive sometimes.”

Perez and Pratto both went deep off of White Sox starter Lucas Giolito, a familiar foe for the veteran Perez but not so much the rookie Pratto. Perez is slugging .903 against Giolito in his career, with a 1.322 OPS in 31 at-bats against the right-hander.

Naturally, Perez joked about the advice he shared that led to Pratto’s big night.

“I [taught] him how to do it,” Perez said smiling, slinging an arm around Pratto’s shoulders.

“I just watch him,” Pratto responded. “You guys found out my secret.”

Seven of Pratto’s last eight hits have gone for extra-bases. The one that didn’t land for extra bases was a single into right field Tuesday during an eight-pitch battle with White Sox lefty Tanner Banks, brought in specifically by bench coach Miguel Cairo -- managing in place of Tony La Russa, who missed the series opener at the direction of his doctors -- to face the Royals’ lefty-heavy part of the lineup.

“To stay in there and just put together a good at-bat -- he trusts his eye,” Matheny said. “He trusts his strike-zone awareness. … He has an idea of what he wants to do when he goes up there. And when he’s seeing the ball like he is right now, good things happen with that swing path.”

Pratto has been in the big leagues for all of 37 games, but he has responded to the struggle with adjustments of his own, much like he did in the Minors.

“It’s just an ongoing process,” Pratto said. “It’ll lift you up and beat you down at the same time. The ones that come back and make the adjustments are the ones who last.”