KANSAS CITY -- The momentum the Royals rallied behind in the bottom of the ninth inning Saturday night came too late to salvage their game against the Cardinals.

They’ll need it on Sunday to salvage the series.

Three runs in the ninth wasn’t enough to overcome the Cardinals’ offense in the Royals’ 9-4 loss at Kauffman Stadium. St. Louis scored four runs in the seventh and three in the ninth to hand Kansas City its third consecutive series loss and second to its I-70 rivals on back-to-back weekends.

The Cardinals are now 42-21 at Kauffman Stadium since the two teams began playing there in 1973. On Saturday, they played in front of the Royals’ biggest crowd since 2018 -- a paid attendance of 35,784.

And for most of Saturday, that crowd was treated to a low-scoring affair. The Royals scored one run off Jon Lester in 5 2/3 innings, and Brad Keller had allowed two -- both unearned after third baseman Emmanuel Rivera’s errant throw and shortstop Nicky Lopez’s errant play -- through 6 2/3 innings. He commanded the zone with the best sinker he’s had all season and struck out eight by mixing in his four-seamer and changeup to keep the Cardinals off balance.

The last time Keller faced the Cardinals, he lacked fastball command and walked five in five-plus innings.

“It’s a big adjustment since my last start against these guys where I might have thrown one fastball for a strike,” Keller, who was charged with four runs (two earned), said. “Today, I felt like it was the exact opposite.”

Keller pitched into the seventh inning for the fifth time in his last seven starts and navigated his defense’s errors in the fifth without significant damage done. After needing 25 pitches to get through the fifth, he breezed through the sixth with 12 pitches.

“One thing I really tried to focus on was keeping my composure throughout that inning,” Keller said. “Earlier this year, it seemed like innings that started out that way always seemed to snowball into some crooked numbers.

“Early on, my focus would go somewhere else and I would leave a slider in the middle of the plate or fastball in the middle of the plate and they’d do damage on it. Today, I was able to focus and get through it.”

Keller allowed back-to-back singles to Edmundo Sosa and Tommy Edman with two outs in the seventh, and manager Mike Matheny went to Josh Staumont, who hadn’t allowed an inherited runner to score this season until last weekend against the Cardinals.

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.

“Josh does a nice job for us,” Matheny said. “Take a good shot at keeping it where it is. Trust our offense to do something with our bullpen when they make that change.”

Greg Holland allowed another three runs in the top of the ninth inning. One came on a near collision between Michael A. Taylor and Andrew Benintendi in left-center, but Taylor was able to make the catch to keep it to a sacrifice fly. One pitch later, Arenado hit it to the exact same spot. But Benintendi pulled back, and the ball dropped on the warning track for a two-run ground-rule double. That play, coupled with Lopez’s error at shortstop in the fifth, have typically been no-doubt outs for the Royals this year.

“Those guys have been really impressive in the outfield this year,” Matheny said. “They’ve covered a very big outfield really well all season long. There are going to be balls that are just tough to get to at times.”

By the time the Royals’ offense had an answer, it was too late. On the day they honored Whit Merrifield’s new franchise record with 422 consecutive games played, he roped a two-run double off Andrew Miller and scored on Carlos Santana’s RBI single, which broke an 0-for-21 skid for the first baseman.

The Royals left nine on base Saturday and were 3-for-9 with runners in scoring position after entering the game hitting .163 in scoring situations in the last 14 games.

“Just staying engaged and not giving at-bats away, that’s important for individuals,” Merrifield said. “Hopefully we can take that momentum into tomorrow and salvage the series.”