KANSAS CITY -- With two on and nobody out to begin the seventh inning, the Royals bullpen was stirring, preparing to help starter Michael Wacha out of a sticky situation in a tie ballgame.

Wacha turned to his defense for help instead, watching the infield turn an atypical 3-4-5 double play to get the lead runners out. After a quick talk with catcher Freddy Fermin to get back on track, Wacha finished the frame unscathed with a strikeout.

The Royals stole the momentum with their heads-up play and turned it immediately into four runs in the bottom of the seventh inning en route to their 8-3 series-finale win over the Cardinals on Saturday night at Kauffman Stadium.

Playing first base on the 13th anniversary of his Major League debut, Royals captain -- and No. 13 -- Salvador Perez was instrumental in getting that double play started. After infield coach José Alguacil alerted Perez to take a few steps backward, Tommy Pham hit a sinker almost directly at Perez, who fielded the sharp hopper.

Immediately, Perez heard Garcia at second base yelling, “Get it to me, get it to me.”

Perez fired it to second base for the first out, and it was a quick enough throw that Paul Goldschmidt -- who hit a two-run homer off Wacha in the second inning and walked in the seventh -- was in a no-win situation, especially because of the big secondary lead he took off second base. Garcia clocked that lead and was adamant on getting Goldschmidt out as the lead runner.

“It’s better for the pitcher to have a man on first base than on third base,” Garcia, a shortstop by trade, said. “Anything can happen with the runner on third.”

When Goldschmidt broke for third, Garcia whipped the throw to third baseman Paul DeJong, and Wacha was suddenly working with two outs and a runner on first base.

“It was a tough read for Goldy there,” Cardinals manager Oliver Marmol said. “You don't know if [Perez] caught it, so you have to wait to see, and then by that time, it's over. That’s an odd line drive and tough read there.”

Because Wacha was able to keep the Cardinals quiet in the middle innings, finishing with just the two runs allowed in seven innings, the Royals were able to mount a comeback. Wacha has won five of his last seven starts since the beginning of July, with a 2.74 ERA in that stretch.

“When [Wacha is] going out there on the mound, he’s going out there for one reason, and that’s to beat you,” manager Matt Quatraro said. “And that’s what he tries to do. I’m really, really happy he ended up getting that win.

"He more than deserved it. Just to keep us in that game, when you’re down two, then down one, then tied. Just keep going out there and get after it. That’s what he does.”

Perez and Garcia then played big roles in the Royals’ big inning: Garcia knocked in the go-ahead run with his RBI single -- his third RBI in five games on this homestand -- notched his team-leading 28th steal of the season and scored on Bobby Witt Jr.'s triple.

The K was rocking after Witt’s 11th triple of the year, MVP chants making their way through the ballpark again.

Perez turned it up even louder with his 21st home run of the season. The swing before, Perez took one out to left field, but it landed just foul. So, Perez took the next pitch to the opposite field, a Statcast-projected 395-foot two-run blast to right-center field.

“Most of the time when you hit a foul-ball homer, you follow with a strikeout or a ground ball out,” Perez said, laughing. “You miss the next one. So, thank God [I didn't].”

The Royals added on two in the eighth with Kyle Isbel’s triple -- his third hit of the night -- and Witt’s third RBI.

Unlike Friday, the Royals’ bullpen was able to hang on for the lead.

After reliever Kris Bubic allowed one run and put runners on first and second with two outs, Lucas Erceg entered to face Goldschmidt and got a strikeout with a filthy slider, causing the packed Kauffman Stadium to erupt once again.

Erceg was fired up coming off the mound, and he was able to return for the ninth, work around another jam to notch a four-out save -- his first save as a Royal.

“It was a big situation in the game,” Erceg said of the eighth inning. “And I know the Royals and the Cardinals have somewhat of an interstate rivalry. In that situation, I was just fired up to get out of it, help the team secure the lead.”