ST. LOUIS (AP) -- Luis Rivas made the most of his unexpected opportunity.
"I got ready before the game. That's what I do every day," Rivas said. "I was ready to play ball."
Nady hit a three-run double in a four-run first and Rivas finished the five-run third with a two-out drive to left-center. Rivas' third home run of the season came on the second pitch he saw from Kelvin Jimenez, who entered to face Rivas in relief of rookie starter Mike Parisi.
"It feels good, amazing," Rivas said of his slam. "It's my first one, so it's pretty good."
Wilson is dealing with a strained calf.
Jose Bautista singled four times for his first career four-hit game and Freddy Sanchez had three hits for the Pirates, who finished with season highs for runs and hits (19). It was their most runs since a 15-1 victory against St. Louis last Aug. 1.
"With a big lead, it's even more important to get ahead and let the defense make some place and they made some great plays," Maholm said. "It made me relax a little bit more."
Paulino hit an RBI single in the third and a two-run drive in the sixth. Sanchez also homered for the Pirates.
The Pirates haven't given Maholm much run support this season. They scored three runs or fewer in seven of his 10 starts before Saturday and, in his previous three games, scored four total -- all in a loss to Chicago in his last start.
Pittsburgh got timely hits against St. Louis throughout the game, scoring its final 10 runs with two outs.
"Our guys have been scrappy all year and take a lot of pride in not giving away at-bats," manager John Russell said.
Parisi (0-2) lasted just 2 2/3 innings in his first start after eight relief appearances since being recalled May 4 from Triple-A Memphis. He was charged with eight runs and eight hits, walked three and struck out two.
"That was a learning experience for him," St. Louis manager Tony La Russa said. "I mean, he's out there firing instead of pitching. He's got an arsenal to pitch with. He'll benefit from the experience."
The lopsided loss came in La Russa's 2,000th game with St. Louis. He surpassed Red Schoendienst for most games as a Cardinals manager. Troy Glaus hit his third home run and Albert Pujols had two hits.
Maholm (3-5) allowed one run and four hits in 6 2/3 innings to earn his first win since April 27 against Philadelphia. He struck out five and walked none.
"I feel like I executed pretty well and the offense, of course, they swung the bats great, he said. "Overall, it was a great night."
After throwing a two-hitter against the Phillies, Maholm went 0-3 in his next five starts and his ERA climbed nearly two points to 5.11.
The game was played in a driving rain from the second through the sixth. The start of the seventh was delayed about 10 minutes as the ground crew worked on the mound. ... Rivas' slam was the first for Pittsburgh since Sanchez hit one Aug. 28, 2007, against Cincinnati. ... Glaus was hitless in his previous 11 at-bats before hitting his home run. His previous homer came May 13, also against Pittsburgh.