Matt Carpenter belted a two-run homer in his first at-bat in place of Beltran, while Kyle Lohse worked out of a number of jams over a 5 2/3-inning stint as the defending World Series champion Cardinals took a 2-1 lead in the best-of- seven set after waiting out a stoppage of nearly 3 1/2 hours during the bottom of the seventh caused by thunderstorms.
Beltran left after one inning with a left knee strain the veteran outfielder suffered while grounding into a double play in his only plate appearance.
The Giants came through with several clutch hits in evening this series with a 7-1 triumph in San Francisco in Sunday's Game 2, but stranded 11 baserunners while going 0-for-7 with men in scoring position in this one.
"I think we had our chances throughout the game," said San Francisco manager Bruce Bochy. "It was a frustrating game."
Pablo Sandoval finished 2-for-5 and drove in the Giants' lone run, while starting pitcher Matt Cain (1-2) permitted all three St. Louis runs over the first 6 2/3 innings.
Marco Scutaro was in the San Francisco lineup after exiting Game 2 with a strained left hip, the result of a hard slide the second baseman endured from the Cardinals' Matt Holliday, and also collected two hits.
Carpenter, the Cardinals' top pinch-hitter over the course of the regular season, immediately demonstrated his value off the bench with his club trailing 1-0 in the bottom of the third inning.
Cain set down seven of the first nine St. Louis hitters before giving up a single to Jon Jay with two outs in the inning, and the 16-game winner couldn't sneak a slider past Carpenter as the super sub battled back from an 0-2 count to send a blast over the home bullpen in right field to put the Cardinals in front.
"I was just trying to grind out these at-bats and fight when I'm up there, and tonight was an example of that," Carpenter said. "(Cain) threw a slider across the middle of the plate and I was able to put a good swing on it."
The Cardinals generated little offense off Cain over the next three innings, with the steady right-hander yielding just a single hit over that span.
San Francisco had considerably more scoring opportunities during that time frame, but couldn't cash in due to a lack of timely hitting and Lohse's clutch pitching.
Angel Pagan flied out to leave two men on in the fourth, while Scutaro's leadoff single an inning later was erased when Lohse induced Sandoval to hit into a double play. Another San Francisco threat was thwarted in the sixth when Trevor Rosenthal relieved Lohse with runners at first and second and retired Pagan for the final out.
The Giants again made a bid in the seventh, when Sandoval and Buster Posey delivered back-to-back one-out singles against Edward Mujica. However, Mitchell Boggs came on to strike out both Hunter Pence and Brandon Belt and preserve St. Louis' one-run edge.
St. Louis would get to Cain for some insurance in their half of a seventh that was stretched out by the massive delay. David Freese stroked a one-out double and Daniel Descalso was intentionally walked to put two on for Pete Kozma, with the rookie shortstop serving a single to center that loaded the bases. Pinch-hitter Shane Robinson then hit a soft grounder to second that plated Freese and gave the Cardinals a 3-1 advantage before the skies opened up.
"(Robinson) just didn't hit it hard enough for a double play," Bochy remarked. "It was a big run, but as you saw, we couldn't score again. Their bullpen did a good job on us."
When play finally resumed after an interlude of three hours and 27 minutes, Javier Lopez took over for Cain and retired Jay to prevent further damage.
San Francisco's bats remained cold following the break, however, as Motte set down all six hitters he faced to close out the drawn-out contest.
The Giants' only scoring occurred in the top of the third, when Scutaro followed Pagan's leadoff single with a double down the right-field line and Sandoval advanced both runners on a groundout.
Game 4 will take place Thursday at Busch Stadium beginning at 7:07 p.m. CT. Adam Wainwright will get the call for the Cardinals, with two-time NL Cy Young Award winner Tim Lincecum tabbed to make his first start of this postseason for San Francisco.
Game notes: Carpenter now has five hits in six career at-bats against Cain ... The Cardinals moved to 9-2 all-time in NLCS Game 3's and are now 6-0 at home under such scenarios ... San Francisco entered the game having won its last five postseason away tilts, having not lost on the road in the playoffs since dropping Game 3 at Texas in the 2010 World Series ... Scutaro is now 6-for-13 in the NLCS and is batting .360 (9-for-25) during a six-game hitting streak this postseason.