"He came up to me and I figured we were going to go over their lineup, do some scouting," Volquez said. "But all he said was, 'Go out there and win.'"
Volquez compiled with those simple instructions, tossing a complete game six-hitter to win his fourth straight start in a 9-1 victory.
Neil Walker, Josh Harrison, Russell Martin and Andrew McCutchen all drove in two runs for Pittsburgh, which avoided being swept in the four-game series.
Volquez (8-6) has a 0.90 ERA in winning four consecutive starts for the first time in his career. He struck out five and walked two in recording the second complete-game win of his career.
He allowed just one hit as a member of the San Diego Padres in beating Houston 1-0 on July 19, 2012.
"He used his breaking ball effectively and he got outs when he needed them," Pirates manager Clint Hurdle said. "It's about throwing strikes and changing speeds. It was a real good effort."
Volquez seemed to get better as the game went along. He needed a season-high 114 pitches to give the Pirates their first complete game of the season.
"He had command of all of his pitches," St. Louis infielder Matt Carpenter said. "We just weren't able to get anything going."
Volquez allowed the leadoff batter to reach base in each of the first four innings. He then gave up just two hits over the final five.
"When he gets past the fifth, he smells the finish," Hurdle said.
Shelby Miller (7-8) allowed four runs in five innings. He walked four and struck out one.
Walker extended his hitting streak to a season-high 12 games with a two-run double in the fifth that extended the Pirates lead to 4-1. McCutchen started the three-run uprising with a run-scoring single that broke a 1-all tie.
McCutchen drove in a run in the sixth with a sacrifice fly. Harrison added a two-run double in the inning that made it 6-1.
Martin homered off Jason Motte in the ninth. Martin drove in his 500th career run in the first inning.
The Pirates had been held to six runs in losing the first three games of the series. They were a combined 2 for 25 with runners in scoring position in those losses.
On Thursday, they came up with several key hits in a 4-for-11 effort with runners in scoring position.
"We took advantage of some mistakes and some opportunities and we were able to play our game," Walker said.
The Cardinals were playing without All-Star catcher Yadier Molina, who tore a ligament in his right thumb in Wednesday's 5-2 win. Molina will undergo surgery on Friday and is expected to miss 8 to 12 weeks.
"I think it was a tough night for our club in general," manager Mike Mathney said. "We just didn't look right from the beginning."
St. Louis tied it in the third on a sacrifice fly by Carpenter. Kolten Wong began the inning with a single.
Miller lost his third straight decision.
"I didn't do a good job of getting ahead in the count," Miller said. "I ended up walking guys and they took advantage of the situation."
NOTES: St. Louis OF Allen Craig, mired in an 0-for-13 skid did not play Thursday. ...The Cardinals open a three-game series in Milwaukee on Friday. Joe Kelly (1-1, 0.59) will face Yovani Gallardo (5-5, 3.45) in the first game. Kelly is making his first appearance since straining his left hamstring on April 16. ... Pittsburgh will travel to Cincinnati for a three-game series beginning Friday. LHP Jeff Locke (2-1, 3.08) will face Mat Latos (2-1, 2.41) in the opener. ... St. Louis C Tony Cruz, who is replacing Molina, allowed a passed ball in the sixth that brought in a run. ...There are now just three teams without a complete game this season — Kansas City, Colorado and the Chicago Cubs.