KANSAS CITY — With two outs in the top of the seventh inning Saturday night, Brad Keller had pitched well enough to keep the Royals within reach, only chasing a one-run deficit to the Cardinals.

When Keller handed the game over to the Royals bullpen, though, the Cardinals offense quickly took over. A four-run inning, with two runs handed to Keller and two to Josh Staumont, gave the Royals an eventual 9-4 loss at Kauffman Stadium, their third consecutive series loss and second to the Cardinals on back-to-back weekends.

The Cardinals are now 42-21 at Kauffman Stadium since the two teams began playing there in 1973.

For most of Saturday, Keller pitched like the Royals needed him to pitch. He allowed two runs — one earned after third baseman Emmanuel Rivera’s error in the fifth inning — through 6 2/3 innings, with eight strikeouts and two walks. It was a completely different start than his previous start against the Cardinals last weekend, when he walked five in five-plus innings.

But Keller faced trouble in the seventh. With two outs, one being on Salvador Perez’s no-doubt throw to catch Harrison Bader stealing second, Keller allowed back-to-back singles to Edmundo Sosa and Tommy Edman, putting runners on first and third and ending Keller’s night.

Staumont entered and threw a wild pitch to put Edman on second base. Then Paul Goldschmidt dumped a single into center field for two runs before Nolan Arenado hit a moonshot to left field for his second homer in as many days. All four runs came with two outs, and Greg Holland allowed another three runs in the top of the ninth inning.

By the time the Royals offense had an answer, it was too late. Four consecutive hits and three runs in the ninth inning gave some momentum, but time ran out with the lead they were chasing too difficult to reach.