The Detroit Tigers extended their series lead over Oakland while the Nationals recorded the first playoff win by a team from the US capital since 1933 with a 3-2 victory over St Louis.
MLB playoffs: Washington end 79-year victory drought
Tyler Moore smacked a two-run single in the eighth inning to give the Washington Nationals a 3-2 victory over St. Louis in the opening match of their Major League Baseball playoff at Busch Stadium.
The Nationals, whose 98 triumphs were the most of any major league club this season, collected the first playoff victory by a team from the US capital since the 1933 World Series.
Michael Morse opened the eighth inning by reaching base on an error by Cardinals shortstop Pete Kozma and took third on a single by Ian Desmond, who moved to second on a sacrifice bunt by Danny Espinosa.
Pinch-hitter Moore then entered for the Nationals and blasted a two-out line drive hit to right field that brought home the deciding runs.
"I was able to just stick it out, put the bat on one and flair it out to right," he said afterwards.
"I just tried to settle my nerves down and put it in play the best I could."
The Cardinals have the chance to strike back in the second game of the five-game series later today.
The Oakland Athletics urgently need to make home advantage count after sliding 2-0 behind in their American League play-off against the Detroit Tigers.
Don Kelly hit a sacrifice fly to score Omar Infante with the winning run as the Tigers beat Oakland 5-4 to move within one win of facing San Francisco or Cincinnati.
He firstly brought the score level at 4-4 with a run on a wild pitch from Ryan Cook, then drove in the winning run with a sacrifice fly off Grant Balfour, with Omar Infante the man to score.
"It's unbelievable," said Kelly. "I was just trying to get a pitch to hit. It was a great opportunity."
The series now switches to Oakland on Tuesday, with the hosts knowing they must win all three remaining games to make the next round.
Cincinnati starter Bronson Arroyo dominated from the mound to shut out the San Francisco Giants 9-0 as the Reds seized control of their National League Division Series with another road victory.
Arroyo allowed just one hit over seven innings to guide the Reds to a 2-0 lead in the best-of-five series, which moves to Cincinnati on Tuesday.
Ryan Hanigan's two-run single put Cincinnati ahead 4-0 in the fourth inning and the visitors delivered the knockout blow in the eighth, where they tacked on five more runs.
Joey Votto finished with three hits while Brandon Phillips added a pair of hits and is now 5-for-10 with a homer and four RBIs for the series.
The New York Yankees left it late to dampen the Baltimore Orioles' first post-season appearance in 15 years with a 7-2 victory in the rain-delayed opener of their American League Division Series on Sunday.
New York erupted for five runs in the ninth inning, snapping a tense 2-2 tie and spoiling the party for the 47,841 orange-clad fans on a chilly night at a sold-out Camden Yards.
Russell Martin opened the inning by knocking a 91 mph (146.45 km) belt-high, fast ball from Orioles' All-Star reliever Jim Johnson into the left field seats.
Martin's tie-breaking homer was followed by an RBI single by Ichiro Suzuki, a two-run double by Robinson Cano and a sacrifice fly by Nick Swisher.
Southpaw CC Sabathia got the win for New York, pitching 8 2/3 innings, before giving way to reliever David Robinson for the final out of a game that started two-and-a-half hours later than scheduled due to intermittent rain.
Follow us @SprtNationalUAE