Updated

The St. Louis Cardinals dominated the first two games of the I-70 Series as they have dominated the Royals in Kansas City since interleague play began.

The Cardinals outscored the Royals 21-6 in victories Monday and Tuesday at Kauffman Stadium. St. Louis improved to 34-19 in regular-season games played at Kansas City.

The series concludes with games Wednesday and Thursday in St. Louis, where the Royals have a winning record. Kansas City is 15-12 in new Busch Stadium and 20-19 overall in St. Louis.

"I kind of like it," Royals manager Ned Yost said of the home-and-home, four-game series. "I think it's cool to be able to play two here and two there. I've got no issue with it."

Yost has a bigger issue with his pitching staff, which allowed six home runs to the Cardinals in the two games at Kansas City.

There was ample Cardinals red in the stands at Kauffman Stadium.

"But we get that when we go back to St. Louis; there's a lot of Royal blue in the stands," Cardinals manager Mike Matheny said. "It's just part of this local rivalry. I think fans, there's a lot of St. Louis people that have been repositioned out here and vice versa, so it's nice to have some red in the stands. Just a good crowd overall and a good atmosphere."

After sitting Sunday and Monday, third baseman Jedd Gyorko returned to the Cardinals' lineup Tuesday and crushed a three-run homer.

"This is only my second time being a part of it, so still relatively new," Gyorko said of the I-70 Series. "But games are on the schedule, so every game is just as important as the next. We've just got to go out and play ball."

The Cardinals (57-56) have won four straight for the first time since June 28-July 1, and they have moved one game above .500 for the first time since June 1. They also picked up a game Tuesday on the Cubs, who lost 6-3 to the San Francisco Giants, moving within 2 1/2 games of Chicago for first place in the National League Central.

The Cardinals will send right-hander Mike Leake to the mound Wednesday in the third game of the series. Leake is 7-10 with a 3.34 ERA in 22 starts.

He ranks among the top 10 in the National League in ground-ball percentage (56.3 percent), walks per nine innings (2.14) and quality starts (14). Low run support (4.14 per start) largely explains why he does not have a better record.

This will be his second career start against Kansas City. He held the Royals to three runs (two earned) in seven innings in a 4-2 Cardinals loss on June 30, 2016.

Brandon Moss is 3-for-8 with a home run off Leake, but with no designated hitter in a National League park, he might not be in the lineup.

The Royals will counter with right-hander Trevor Cahill.

Cahill (4-3, 4.13 ERA) will be making his 14th start of the season and his third for the Royals since being acquired in a six-player trade with San Diego on July 24.

The 29-year-old right-hander has a 7.27 ERA and no-decisions in his first two Kansas City starts. He has allowed seven runs and 14 hits, including four home runs, and four walks in 8 2/3 innings.

Cahill is 1-3 with a 3.55 ERA in 13 career outings, including five starts, against the Cardinals.

The Royals (57-55) are now four games behind Cleveland in the AL Central and in a virtual tie with Seattle and Tampa Bay for the second AL wild-card spot.