SAN DIEGO -- Matt Kemp and Justin Upton each had two RBIs in a seven-run seventh inning on Saturday night as the San Diego Padres routed the St. Louis Cardinals 8-0 at Petco Park to stretch their winning streak to five.

But to hear Padres manager Pat Murphy tell it, the key inning was the top of the seventh when the Padres went righty-lefty-righty from their bullpen to maintain a 1-0 lead after St. Louis put the tying run at third with no outs.

"That was a pretty special win," Murphy said after the Padres posted a second straight victory against the winningest team in the major leagues. "That's how we scripted it ... and how it came out was very emotional in that situation."

The Padres had led 1-0 since the fourth after catcher Derek Norris led off with a triple and scored on a grounder to second by rookie center fielder Travis Jankowski.

The Cardinals opened the seventh with a double by catcher Brandon Moss and a single by center fielder Tommy Pham against Padres starter Ian Kennedy (8-11) to put runners at the corners with no one out.

With Cardinals pitcher Carlos Martinez (12-6) hitting, Murphy brought in right-handed reliever Shawn Kelley, who struck out Martinez on three pitches after Martinez failed to get down a bunt.

That brought up Kolten Wong, who entered the game two innings earlier after second baseman Matt Carpenter was ejected by plate umpire Chris Segal for arguing a called third strike. To counter the left-handed-hitting Wong, Murphy brought in left-handed specialist Marc Rzepczynski, who struck out the struggling infielder (four hits in his previous 33 at-bats) on five pitches.

Next was right-handed-hitting left fielder Stephen Piscotty, who had already struck out twice to end an inning with a runner in scoring position. Murphy countered with right-handed reliever Bud Norris, who got Piscotty on a called third strike after a seven-pitch battle.

"That was the turning point," Kelley said. "It was exciting. There was a lot of energy in the dugout after we got out of the seventh. It's nice to have a lefty like Rzepczynski to go to. That kind of establishes roles."

Cardinals manager Mike Matheny said, "That inning took some wind out of our sails for sure. We've been on the other side of that and it's like your back is up against the wall."

In the bottom of the decisive seventh, the Padres scored seven runs (four earned) against Martinez and three relievers. San Diego sent 11 hitters to the plate and got seven hits.

"It was one of those innings that kind of blew up on us," Matheny said.

In addition to the two-run hits by Kemp (a single to extend his hitting streak to 14 games) and Upton (his second double of the game), the Padres got two singles and a RBI each from pinch-hitter Alexi Amarista and Jankowski.

Jankowski, who has batted ninth in each of his first two major league games, became only the seventh player in Padres history to drive in a run in each of his first two games.

"The offense is starting to realize how to trust in each other," Murphy said. "No one has to do it alone."

Five straight victories equal the Padres' longest winning streak of the season. And San Diego is 9-2 in its last 11 games to climb within one game of .500 for the first time since it was 32-33 on June 14 -- the day before Bud Black was fired as manager.

Kennedy allowed seven hits and a walk while striking out 10 in six-plus innings. Five relievers combined to finish the Padres' fourth shutout of the season and the 10th thrown against the Cardinals.

"Ian was lights out," Murphy said. "He was focused. That was as good a performance as I've seen all year."

NOTES: Matt Carpenter made his fourth start of the season at second base for the Cardinals Saturday night as slumping Kolten Wong got a night off. Manager Mike Matheny hinted Wong, who had started111 games at second, might get more than one day off. But Wong entered the game in the fifth after Carpenter was ejected by plate umpire Chris Segal for protesting a called third strike. ... LHP Marco Gonzalez, who won two games in the Division Series last October against the Dodgers, allowed six hits over five shutout innings for the Cardinals' Triple-A Memphis affiliate to get his first win of 2015. ... Regular 2B Jedd Gyorko started his second game at shortstop for the Padres Saturday. ... LF Justin Upton got the 600th RBI of his career Friday night against the Cardinals. ... The Padres scored their 500th win at Petco Park Friday. The Padres are 500-450 at home since the downtown facility opened in 2004.