And it ensured the Cardinals of not being leapfrogged in the National League Central standings by the Reds, who still sit a half-game behind St. Louis after earning their own victory on Monday. The Cardinals have not trailed in the division all year.
"There are no secrets around here -- we needed to get things turned around," manager Mike Matheny said. "Sometimes one at-bat can do that. We're not going to be slow to acknowledge how big that is for all of us."
Much more critical than the current standings is the team's current state of play, and there was much to like about St. Louis' overall performance in the first game of a seven-game homestand.
For a change, it was defensively sound and showcased an efficient, effective starting pitching performance. And the offense, while not explosive early, did its part when run-scoring opportunities came up late.
"Everybody's pulling together, trying to make a win," said Greene, who finished with a three-hit night. "It was great for us to come back and get the 'W' today."
Greene's home run -- his fourth of the season -- came a half-inning after the Cardinals' bullpen let another lead slip away. Matheny managed his bullpen in the eighth in a way that showed, to use his words, "extreme urgency" to find a way to win.
With his team holding a 2-1 lead, Matheny pulled starter Jamie Garcia, with a pitch count of 92, after Chris Denorfia led off the eighth with a double.
"[It was] realizing that we're going to take our best shot," Matheny said.
Right-hander Mitchell Boggs did his part, recording two outs as Denorfia advanced to third. The ball then went to lefty Marc Rzepczynski for a left-on-left matchup with Yonder Alonso, but Rzepczynski walked the cleanup hitter on four pitches.
Matheny then called upon his closer. Eyeing a four-out save, Jason Motte instead surrendered the lead. Jesus Guzman launched a double to left-center, allowing both runners to score.
"I didn't get it up and in like I wanted to," said Motte, who suffered his third blown save of the season.
That also continued a trend of wobbly relief. The Cardinals' bullpen, which entered the night with a 6.09 May ERA, has now been scored upon in 13 of the team's last 14 games.
Motte did later rebound, giving his team a scoreless ninth inning to earn the victory.
"I didn't have a choice," Motte quipped.
Motte took the mound in the ninth with a one-run lead, provided by a bloop and blast in the bottom half of the eighth. Yadier Molina reached on a one-out, broken-bat single. Greene then drove him home when he crushed a first-pitch fastball from reliever Andrew Cashner out to right-center.
"A guy like that, you have to be ready to hit," Greene said. "If it's anywhere around that middle of the plate you have to be ready. I was just trying to see the ball and make sure it was a good pitch to hit."
The pitch, which Cashner defended after the game, read 101 mph on the radar gun.
"You've just got to tip your cap and go on," Cashner said. "That's the pitch I wanted to make."
Though Garcia wasn't able to win consecutive starts for the first time this season, he did help key Monday's victory. His seven-inning outing was much more reminiscent of what the Cardinals routinely received in April. He was also just the second Cardinals pitcher to go seven innings in a start since May 9, the start of the team's 2-8 skid.
"I was able to keep the ball down, get ahead and execute my off-speed stuff," Garcia said. "We needed this win."
The Padres did get to Garcia in the second, scoring once after a sequence that included a single, balk and sacrifice fly. Garcia cruised from there and then worked his way around additional trouble in the top of the seventh to keep the deficit at one. He recorded two strikeouts to strand runners at second and third in that frame.
In the bottom half of the inning, Garcia's single helped the Cardinals take a short-lived lead against Padres starter Clayton Richard.
Greene began the inning with a single and moved to second on a groundout, leaving Matheny with the choice of batting his starter or summoning a pinch-hitter with one out. Matheny, going with gut, stuck with Garcia.
"I just felt pretty good about our offense getting something going and he's as good as we can have out there," Matheny said. "I figured he had as good a shot as anybody."
Garcia answered with an infield single to short. It was Garcia's sixth hit in 22 at-bats this season.
Rafael Furcal followed with a game-tying RBI single. Garcia, who raced from first to third on the hit, was then in position to give the Cardinals a 2-1 lead on Matt Carpenter's groundout.
"We just need to get something positive going," Matheny said. "They've been fighting. They deserve some wins to get some momentum moving."