Rookies in the postseason, the Washington Nationals played like poised veterans.

The Nationals escaped a bases-loaded jam in the seventh inning, Tyler Moore blooped a two-out, two-run single in the eighth and Washington beat the defending World Series champion Cardinals 3-2 Sunday in an N.L. playoff opener in St. Louis.

The Nats have just four players with postseason experience on the roster, but they have the series lead.

"Not many people have probably watched too many Nationals games, but we have a great starting rotation and a great bullpen," said Ian Desmond, who singled for his third hit in the go-ahead rally.

The Nationals, who had never come close to making the playoffs since moving from Montreal for the 2005 season, overcame a wild start by 21-game winner Gio Gonzalez, who arrived in a trade from the A's in the offseason.

They limited the Cardinals to just three hits.

"All the credit in the world goes to the bullpen," Gonzalez said. "I've been saying it all year. The reason why we've been so successful is these guys come in and shut it down."

Reliever Ryan Mattheus defused a bases-loaded, none-out threat in the seventh on two pitches, getting cleanup man Allen Craig to ground into a force out at the plate and then inducing a double-play grounder from Yadier Molina. Craig led the National League with a .400 average with runners in scoring position, and Molina batted .321 in those situations.

"It was a big moment," Mattheus said. "It gave us life. The guys said, 'Hey, we can win this ballgame.' "

And on the first pitch of the eighth, Cardinals rookie shortstop Pete Kozma misplayed Michael Morse's grounder. Desmond followed that error with a hit and, two outs later, pinch hitter Moore slapped a two-strike single to right for a two-run single.

"It's baseball," Cardinals outfielder Matt Holliday said. "They got a guy who throws ground balls and he came in and got two of them. You've got two of the best hitters in the league coming up. It just didn't work out."

Tyler Clippard worked around an error in the eighth, and Drew Storen saved it with a 1-2-3 ninth.

The N.L. East champion Nationals led the majors with 98 wins this season and brought postseason baseball to Washington for the first time since 1933.

"This team is not hanging our heads," St. Louis starter Adam Wainwright said. "We can come back and win this easily."

St. Louis wasted a 10-strikeout gem by Wainwright, failing to capitalize enough on Gonzalez's career high-tying seven walks and frustrating its towel-waving fans.

Yankees 7, Orioles 2: Russell Martin led off the ninth inning with a tiebreaking home run off Jim Johnson, CC Sabathia turned in a sparkling pitching performance and New York beat host Baltimore in the opener of their A.L. divisional series.

Sabathia allowed two runs and eight hits in 82/3 innings to help the Yankees take the edge off the Orioles' first home playoff game since 1997. The husky left-hander went 0-2 in three starts against Baltimore during the regular season, but in this one he returned to form and improved his lifetime record against the Orioles to 17-4.

Sabathia is 6-1 with the Yankees in the postseason, 4-0 in the division series.

With the score 2-all, Martin drove a 2-0 pitch from Johnson into the left-field seats. It was the first of four straight hits off Johnson, who led the majors with 51 saves. Raul Ibanez and Derek Jeter followed with singles, Ichiro Suzuki drove in a run with a swinging bunt and one out later, Robinson Cano hit a two-run double.

In his seven prior appearances against New York, Johnson allowed one run in seven innings and had three saves. Nick Swisher capped the five-run ninth with a sacrifice fly off Tommy Hunter.

The start of the game was delayed by rain for 2 hours, 26 minutes.

Rockies: Manager Jim Tracy resigned, stepping down with a year remaining on his contract after the team set a franchise record for losses. The Rockies said a search for Tracy's replacement would begin immediately but gave no time frame for making a hire. Colorado finished last in the N.L. West this year while going 64-98.

Tracy was promoted from bench coach to manager in May 2009. He was voted the N.L. Manager of the Year that season after guiding Colorado into the playoffs.

The Rockies went 294-308 under Tracy.