ST. LOUIS -- The Royals’ quick trip to Busch Stadium turned into a two-game, one-day series with Wednesday’s doubleheader, and within a span of nine hours they swept their way out of St. Louis.

Following a victory in Game 1, the Royals took the nightcap, 8-5, scoring a total of 13 runs on the day and winning their first road series since late May at Tampa Bay. Kansas City began the day two games out of the final American League Wild Card spot and ended the day a half-game behind the Red Sox, the team the Royals are headed east to play next after Thursday’s off-day.

“That was the goal today, coming here and just trying to play some good ball,” said closer James McArthur, who picked up saves Nos. 16 and 17 of the season on Wednesday. “Our offense was relentless all day. And it’s big. It propels us into this next series, especially winning on the road. We’re just going to try to carry that momentum into Boston.”

Making his first start at Busch Stadium since he was a member of the Cardinals’ organization from 2013-19, Royals starter Michael Wacha allowed four runs (three earned) in five innings. But the offense backed him up, starting with MJ Melendez's home run in the third inning to tie the game, 1-1.

And then the Royals just kept piling on with runs in the fourth, fifth, sixth and ninth.

While the Royals will continue to rely on Bobby Witt Jr., Vinnie Pasquantino and Salvador Perez -- who each drove in a run Wednesday night and have a combined 182 RBIs this season -- having run-producers in the bottom half of the order can go a long way to deepen the lineup.

“It is outfield production, but there are nine guys in the lineup,” manager Matt Quatraro said. “We don’t care what position they play, but right now, those guys are producing.”

The Royals have stated publicly their desire to add and upgrade their roster at the Trade Deadline, which is now less than 20 days away. The bullpen will likely be a target, although setup man John Schreiber had a good bounceback inning with a scoreless seventh in Game 2 against St. Louis. Another obvious trade target that’s starting to see internal improvement has been the outfield.

The production coming from Royals outfielders was rough earlier this year, when the unit slashed .204/.268/.322 with a 64 wRC+ in the team’s first 45 games through May 15. In 47 games since then, entering Wednesday, those numbers have improved to a .224/.289/.389 slash line and 87 wRC+, certainly not where they want it to be but better than it was.

Individually, they’ve made progress. In Hunter Renfroe’s last 37 games since May 12, he’s batting .302 with 11 doubles, five homers and 17 RBIs. He knocked two hits in Game 1 and drove in a run in Game 2.

Kyle Isbel has been solid all year while providing excellent defense and scored three of the Royals’ runs Wednesday night from the No. 9 spot, including his solo homer in the eighth inning.

“It’s a spark at the end of the lineup,” Isbel said. “Those guys are so good at the top of the lineup, anybody who can get on base for them is huge for us.”

In Melendez’s last 22 games since June 14, he’s hitting .287 with six doubles, three homers and eight RBIs. He homered and doubled in two games Wednesday.

“I’m feeling better,” Melendez said. “It’s baseball, you’re not always going to have a great day, great at-bats. You’re going to want them back a lot of times. … I’m working on [the adjustments] every day. This game, it can humble you real quick. So just trying to stick with that same process every day.”

Kansas City entered Wednesday 18-25 on the road this year and 5-14 in their last 19 road games, a stretch in which they averaged just 3.3 runs per game. In total this year, they’ve averaged 3.84 runs per game on the road while batting .223 -- contrasted to their 5.16 runs per game and .267 average at home.

So the offense breaking out in two games in one day across the state from their home park could be a big momentum boost heading into a big series against Boston.

“Especially the couple of days off there, to come in and play well for two games against a good team and go into an off-day with that, it’s a lot happier flight, a lot happier off-day,” Quatraro said. “Hopefully we can build on that going to Boston.”