At least the St. Louis Cardinals don't have to face Pedro Alvarez anymore this season.

The Pittsburgh third baseman continued to torch Cardinals pitching, hitting his 26th homer of the season on Wednesday to lead the Pirates to a 5-0 victory.

"It's not like we're just tossing the ball up there," St. Louis manager Mike Matheny said. "He's hit some good pitches but some of it has been poor execution on our part, too."

Alvarez went 23-for-98 (.396) with seven home runs and 23 RBI in 15 games against St. Louis this year as Pittsburgh moved within one game of the defending world champions for the NL's second wild card spot.

Wandy Rodriguez (9-13) worked six tidy innings for the Pirates to pick up his first victory as a starter since being acquired in a trade last month. Rodriguez walked three and struck out three while helping Pittsburgh shut out the Cardinals for the second straight night.

"''We've seen quite a bit of this this year, it's been a lot of feast or famine," St. Louis manager Mike Matheny said. "It's hard to understand it because we certainly have the ability to put something up there every night. You've got to give credit to the other team but it's also happened too many times."

Joe Kelly (4-6) battled control problems during five rocky innings, giving up five runs on eight hits.

"''I fell behind too many hitters," Kelly said. "I went out and tried to attack the bottom of the zone but missed and brought my stuff up and wound up giving up five runs."

The victory helped the Pirates take the season series from St. Louis 8-7, not an insignificant number with both teams battling for a postseason berth. If the two clubs are tied for the second wild card spot at the end of the regular season, the Pirates would have host the play-in game.

There's still a long way to go before the first week of October, particularly for Pittsburgh. Still, the Pirates will head into September still in the mix, something they haven't done in 20 years.

Pittsburgh appeared to be teetering on the edge of collapse following a 4-3 loss on Monday that dropped the Pirates three games back. They responded with a pair of convincing wins behind the streaky Alvarez.

The former first-round pick has finally developed into the lineup-anchoring power hitter the team envisioned when it drafted him four years ago. He's certainly feasted on St. Louis pitching this season.

"''I was just out there trying to compete," Alvarez said. "It's just one of those things."

He gave Rodriguez all the offense necessary in the third. Coming to the plate with two on and two out, Alvarez drilled an 82 mph curveball from Kelly into the right field seats. The ball left the park so quickly Alvarez barely had time to break into his home run trot before it landed.

"''I let the hottest hitter on their team beat me," Kelly said. "I was down 3-1 and hung a breaking ball to a good hitter. I made a bad pitch and he made me pay."

The blast gave the Pirates a 4-0 lead and Alvarez made it 5-0 in the fifth when he doubled with two outs and scored on a single by Josh Harrison.

Rodriguez took advantage of the cushion. He came in 0-4 as a starter with the Pirates after being acquired from Houston on July 24. His only victory came in two relief innings during Pittsburgh's 19-inning victory in St. Louis on Aug. 19.

Pittsburgh manager Clint Hurdle blamed part of Rodriguez's problems on the pressure of trying to validate the trade. Hurdle urged the veteran lefthander to relax, and Rodriguez looked at ease playing with a sizable lead for the first time as a Pirate. The Cardinals managed just three paltry singles against Rodriguez and never got a runner to third.

The Cardinals played without catcher Yadier Molina, who sat out as a precaution following a brutal collision at home with Harrison on Tuesday night. Molina suffered neck, shoulder and arm soreness after Harrison crashed into him trying to score from second.

Tony Cruz started in Molina's place and had two of St. Louis' five hits, but the Cardinals failed to muster any offense as their scoreless streak reached 21 innings.

"''It's just another game," Matheny said. "We've got to come out tomorrow and do something different. That's all."

NOTES: Pittsburgh 2B Neil Walker missed his third straight game with a stiff back. Walker said he's starting to feel better but still has no timetable on a possible return. ... The Cardinals begin a four-game series in Washington on Thursday. Jaime Garcia (7-9, 3.72 ERA) takes on Washington's Edwin Jackson (7-9, 3.72) in the opener ... Pittsburgh is off Thursday and travels to Milwaukee for a weekend series on Friday. Jeff Karstens (5-3, 3.47) faces Milwaukee's Mark Rogers (2-1, 4.28) in the first game.