The start of Saturday's contest was delayed for three hours, 36 minutes by rains that finally moved out of the area.
Arizona will host St. Louis Sunday night, hoping Curt Schilling can repeat his victory in the opening game of the series. Sunday night's winner will take on Atlanta in a seven-game series beginning next Tuesday to determine the National League title and a berth in the World Series.
"It comes down to one game," said Schilling, who will face the Cardinals' Matt Morris. "It's the best-of-nine tomorrow. We've got to come out and we've go to get it done. You figure out how you're going to get it done and you go about doing it tomorrow."
Edmonds put the Cardinals in front with a leadoff homer in the second off starter Albie Lopez and St. Louis took a 4-1 lead in the third when, after starting pitcher Bud Smith walked to open the inning, Vina hit a homer to right. Vina hit just nine homers in 632 regular-season at bats.
"It was a 1-0 count and I was seeing the ball pretty good today and just trying to get a good pitch to hit," Vina said. "Albie threw me a cutter inside and I was able to get the good part of the bat on it."
"He's definitely one of those guys you don't think is going to hurt you and here he is, he ends up hurting you," Arizona first baseman Mark Grace said.
That was good enough for the three pitchers who worked for St. Louis Saturday -- Smith, Dustin Hermanson and Steve Kline.
Smith, author of a no-hitter during the regular season, walked two men in the first inning and gave up an RBI single to Steve Finley.
But from the second through the eighth innings, Arizona could manage just two hits. One of those came from Tony Womack, who led off the third with a double only to be picked off second base by Smith.
Smith worked five innings, after which Hermanson came on to retire nine straight batters. Kline started the ninth and allowed two singles. But Finley was erased in a double play after starting the inning with a base hit, all but wiping out the Diamondbacks hopes for a comeback.
Kline has saved both of the St. Louis wins in the series.