SAN DIEGO -- Another day, another loss, and more frustration for the St. Louis Cardinals.
Unlike last year when a tremendous stretch run lifted St. Louis to the NL wild-card berth and, ultimately, the World Series title, the Cardinals are sinking fast.
Clayton Richard pitched seven strong innings and rookie Yasmani Grandal singled home the go-ahead run as the San Diego Padres handed slumping St. Louis its 11th loss in 15 games, 3-2 on Wednesday.
The Cardinals began the day with a one-game lead over Los Angeles for the second NL wild card. The Dodgers, who played later at Arizona, host St. Louis in a crucial four-game series starting Thursday night.
"We can't depend on the other teams to keep losing," Cardinals pitcher Kyle Lohse said. "We have to take care of our own business. We have a big series coming up."
But the Cardinals need to find answers in a hurry. They have lost eight of their last nine road games and are in the midst of playing 13 of 16 away from home.
"We're going through a rough stretch, but at the same time, we're still in the hunt," said right fielder Matt Carpenter, who homered but hurt his club with a key error.
Carpenter's misplay on Cameron Maybin's double in the fifth allowed an unearned run to score.
"I was trying to be aggressive and trying to get around where I could keep him from getting a double," Carpenter said. "The ball just got past me and I turned one bad play into another one by missing the cutoff."
"It's unacceptable," he added. "Those are the kind of things that cost you games. It just wasn't a good play."
Carpenter came back and hit a two-run homer off Clayton Richard (13-12) in the sixth to tie the game at 2.
St. Louis put a runner on third with one out in the ninth but was unable to score. World Series MVP David Freese and pinch-hitter Skip Schumaker both grounded out.
Last season, St. Louis went 23-9 down the stretch to capture the wild-card slot. But this team has played the complete opposite in the final weeks.
"Overall, it doesn't matter (how hard the team plays) because it all comes down to whether you win," Cardinals manager Mike Matheny said. "They are still aware of the sense of urgency."
Logan Forsythe hit a solo home run for the Padres, who completed a three-game sweep of St. Louis for the first time since August 1995.
"I take it personally as a compliment to our players that we're able to do that," manager Bud Black said.
San Diego has an NL-best 17-5 record since Aug. 19 and has taken 21 of its last 27 games at home.
"It's exciting when we are winning and playing good baseball like we are," Richard said.
Richard (13-12) outpitched Lohse and gave up only three hits. The left-hander struck out five, walked one and hit a batter with a pitch.
Luke Gregerson pitched the ninth for his seventh save, working around a leadoff double by Allen Craig. After pinch-runner Adron Chambers was sacrificed to third, Gregerson got Freese on a grounder to third before walking pinch-hitter Carlos Beltran. Gregerson then retired Schumaker on an easy grounder to first base to end the game.
Lohse (14-3) had his eight-game winning streak snapped as he allowed three runs -- two earned -- on five hits over six innings. He struck out eight.
"He was sharp right from the beginning," Matheny said. "These are the ones we have to take advantage of."
Lohse's streak spanned 13 starts back to June 26.
Forsythe connected with two outs in the second to give San Diego a 1-0 lead. In his last 13 games, Forsythe has 11 RBIs and 11 runs while raising his batting average 29 points to .289.
Yonder Alonso singled in the fifth and went to third on Maybin's one-out double into the right-field corner. But when Carpenter overran the ball, Alonso scored.
Carpenter homered immediately after Jon Jay's leadoff single in the sixth, but San Diego went ahead in the bottom half on Chase Headley's two-out double and Grandal's run-scoring single.
NOTES: Beltran is in a 3-for-26 slump with one extra-base hit in his last 61 at-bats. ... Padres LF Carlos Quentin, who left Monday night's game with a sore right knee, was held out of the lineup for the second straight game. ... Matheny said LHP Jaime Garcia is still set to pitch Saturday night at Dodger Stadium despite a 2-6 record with an ERA of 6.19 in nine road starts. ... St. Louis opens a four-game series at Los Angeles on Thursday night with RHP Lance Lynn (14-7, 4.04 ERA) facing Dodgers RHP Josh Beckett (1-2, 3.86). ... San Diego is off Thursday before hosting Colorado for three games, starting Friday night with Rockies RHP Tyler Chatwood (4-4, 5.32) opposing Padres RHP Andrew Cashner (3-3, 3.46).