Bumgarner stuck out an arm for the stop sign and Torres applied the brakes in time, giving the National League's worst offense a big boost in the San Francisco Giants' 7-3 victory over the St. Louis Cardinals on Monday.
"I wasn't thinking, just running," Torres said. "When I saw it was out I felt great."
Bumgarner won his second straight after losing his first six decisions and also played a big role at the plate in 90-degree heat with high humidity. The 21-year-old left-hander is from Hickory, N.C.
"This feels like home, it's what I grew up playing in," Bumgarner said. "I like this weather, it feels good to get out there and sweat a little bit."
Kyle McClellan (6-2) was knocked out after four innings in the worst outing of his first season in the Cardinals' rotation, missing a chance to tie for the major league victory lead. Albert Pujols hit his ninth homer and Allen Craig doubled twice with an RBI.
Cody Ross also homered for the Giants, who are last in the National League in runs even after this outburst and had been shut out twice the previous four games. Bumgarner, 4 for 19 at the plate, doubled and scored on Miguel Tejada's hit in the third, then walked on a full count ahead of Torres' second homer of the season in a five-run fourth.
"Walking the pitcher there killed me," McClellan said. "I get him out, that changes everything. Just all in all, not a good game."
Bumgarner (2-6) scattered six hits in seven innings and struggled only in the third when he gave up three straight hits and both runs. It's his seventh straight outing of six or more innings with three or fewer runs allowed, with a 2.12 ERA during that stretch.
"He's pitched well enough to have a much better record. He knows it," manager Bruce Bochy said. "For a young kid he's got great poise, he doesn't get caught up in the elements."
Torres, the Giants' leadoff man, doubled his season RBI total when he drove an 0-1 pitch over the right field wall in the fourth and also doubled. San Francisco won easily despite going 1 for 18 after the grand slam and leaving the bases loaded in the fifth after three straight walks from Miguel Batista.
Torres matched his career high for RBIs with what he believed to be his first grand slam since winter ball in Puerto Rico in 2004 or 2005.
The Cardinals dropped to 9-2 in starts by McClellan, who has yielded a team-high nine homers. McClellan was behind in the count to eight of the first 10 hitters and both of his walks came in the Giants' five-run fourth that made it 7-2.
Manager Tony La Russa said McClellan tweaked his hip in the first inning. McClellan initially said he had not been injured, but later said he had landed awkwardly.
"It raised some concern," McClellan said. "There's nothing wrong."
Aaron Rowand bruised his right hip when he landed on the ball diving into second base on a pickoff attempt in the fifth and was taken out in the bottom of the inning. The team said he was day to day.
Pujols hit his 99th career homer at 6-year-old Busch Stadium -- and first at home since April 23 -- off Ramon Ramirez in the eighth and had an RBI single in the third for his second multi-RBI game in the last four. Only seven players have 100 or more homers in their current stadium.
"He crushed the ball on the home run," La Russa said. "He's hit the ball a lot better than his average."
Ross' homer ended an 0-for-14 slump. ... Attendance of 40,849 was the Cardinals' second shutout of the season. ... Ryan Theriot doubled in the third and has a 13-game hitting streak, tied for the longest active streak in the NL with the Giants' Buster Posey, out for the season with a broken ankle. ... McClellan allowed nine homers in 75 1/3 innings as a setup man last year, and has allowed nine in 67 2/3 innings this year.