KANSAS CITY, Mo. -- The Kansas City Royals overpowered the Chicago White Sox with five home runs to hike their winning streak to four games.

Salvador Perez hit a two-run blast and Mike Moustakas homered twice as the Royals rallied to down the reeling White Sox 7-2 on Saturday night.

Brandon Moss and Jorge Bonifacio added solo shots.

The White Sox lost their eighth in a row. The Royals are tied for second in the American League Central, 1 1/2 games behind the Cleveland Indians.

Kansas City trailed 2-0 entering the sixth inning before Lorenzo Cain led off with a walk to finish the night for starter Mike Pelfrey.

Left-hander David Holmberg (1-3) relieved Pelfrey, who walked six but had allowed two hits.

After retiring Eric Hosmer, Holmberg gave up a two-run homer to Perez to tie it. Moustakas promptly homered, marking the seventh time this season the Royals have gone back-to-back. Moss homered two batters later.

"It was a good inning for us," Moustakas said. "Salvy with the big home run to tie the game. I got a good pitch to hit also and put a pretty good swing on it and it ended up carrying out of the ball park.

"Then Mossy a huge homer behind it. We just put some good swings on some good pitches and they ended up getting out of the yard, a good sixth."

Moustakas homered again in the eighth for his sixth multi-homer game of his career.

"He's definitely locked in," Royals manager Ned Yost said.

Bonifacio led off the seventh with his 12th home run.

Scott Alexander (2-3) picked up the victory after replacing Jason Vargas in the sixth.

Vargas, who had given up 12 runs in 7 2/3 innings in losing his first two July starts, held the White Sox to two runs in the first five innings.

"Obviously, it's pretty hot out there," Vargas said. "It's just one of those things you have to deal with this time of year. In Kansas City, you know you're going to get one or two of these crazy heat waves."

Melky Cabrera homered on an 0-1 Vargas offering in the third. He poked it 360 feet into the left-field seats for his 13th home run of the season.

Cabrera's two-out double to the right-center gap in the fifth scored Tyler Saladino, who had walked. Cabrera had three of the five hits off Vargas in the first five innings and finish with four hits.

"He's a professional hitter, period," White Sox manager Rick Renteria said. "He loves the game, he loves to play. His at-bats and his experience, the time that he's had, obviously, he's gained a lot of knowledge from it and he takes it to the plate every single opportunity that he's had."

Cain led off the fourth with a single for the first Kansas City hit and Hosmer drew his second walk. Perez, however, nearly grounded into a triple play. He hit a slow roller to third baseman Yolmer Sanchez, who stepped on the bag and threw to second forcing out Hosmer. Perez just did beat Yoan Moncada's relay throw to first.

Alex Gordon singled with two outs in the fifth and Whit Merrifield walked. Pelfrey got out of that by retiring Bonifacio on a grounder to second.

"Six walks isn't ideal," Pelfrey said. "I thought I was pretty erratic. I think fastball command was good. I thought the curveball and slider command was pretty bad. The only thing I had that was fairly decent was the split."

NOTES: The Royals recalled RHP Jake Junis from Triple-A Omaha for his fifth stint with the big league club. Junis was 2-4 with a 2.55 ERA in 10 Omaha starts. ... They optioned OF Billy Burns to the Storm Chasers. ... White Sox SS Tyler Saladino made his sixth start at shortstop as Tim Anderson was given a breather. ... The heat index was 112 degrees for the first pitch. Royals LHP Danny Duffy tweeted: "Jesus turn down the furnace, or take the wheel, or something along those lines idk. I feel like I'm medium rare." ... The Royals' bullpen has a 2.32 ERA in 18 July games. ... The Royals' six walks off RHP Mike Pelfrey was the most off a starting pitcher since Miami's Jacob Turner on Aug. 14, 2013. ... LHPs Derek Holland of the White Sox and Travis Wood of the Royals are the Sunday probables for the series finale.