Updated

Favorites to win the NL East this season, the Washington Nationals have been barely playing like contenders.

The Nationals look to get back on track when they continue a three-game series versus the St. Louis Cardinals Tuesday in D.C.

Washington opened a seven-game homestand with Monday's 3-2 loss to the Cardinals and are mired in a four-game home losing streak. Cardinals catcher Yadier Molina singled home Matt Holliday in the top of the sixth for a 3-2 advantage and the St. Louis pitching staff took care of the rest.

Nats starter Dan Haren fell to 1-3 on the season and was reached for three runs and six hits in five innings of work. Haren entered the game 4-0 with a 3.65 ERA in five starts against the Cardinals.

"I want more out of myself than five innings," said Haren. "I have been around for 10 years and I'm used to throwing seven, eight innings every time and I've thrown 200 innings many times.

Ian Desmond and Anthony Rendon both knocked in runs for the Nationals, who struck out 11 times and suffered their seventh loss in 10 games. Rendon continued to fill in for an injured Ryan Zimmerman and made his MLB debut on Sunday in New York. Bryce Harper was 0-for-3 and Jayson Werth ended 1-for-4 with a run scored in the loss to St. Louis.

The Nationals hope Ross Detwiler can get the club in the win column when he takes the ball Tuesday. Detwiler opened the season with two straight no- decisions, allowing just one earned run in 13 innings over that span, and came out on top last Wednesday in a 6-1 win at Miami.

Detwiler shut down the Marlins to the tune of seven innings of one-run ball and is 1-0 with an NL-best 0.90 ERA so far in 2013. The left-hander lost his only regular-season start against St. Louis last Sept. 30, permitting seven runs -- three earned -- in just 2 1/3 innings of a 10-4 decision.

He allowed one unearned run and three hits in six innings against the Cardinals in last year's postseason.

St. Louis will resume a shortened nine-game road trip Tuesday and has alternated wins and losses over its last nine tries.

In Monday's win, Molina was the hero with his go-ahead RBI base hit and Allen Craig ended with two hits and two RBI.

"This is a really tough road trip," said Craig, who batted second in the lineup and leads the club with 14 RBI. "Playing some tough teams, and it's a long one. And anytime you can pull out wins like that in close games, it's definitely a good thing. Tough place to play and to get that win today, it's big."

Carlos Beltran continued to swing the bat well, going 2-for-4.

Shelby Miller got the start for the Cards and improved to 3-1 by limiting the hosts to two runs in 6 2/3 innings with eight strikeouts and two walks. Edward Mujica came on in the ninth for his second save.

Looking to pitch St. Louis to a series win Tuesday will be ace Adam Wainwright. Wainwright lost his season debut, but has rebounded nicely with three straight winning starts. Wainwright, who tossed a four-hit shutout and struck out 12 versus Milwaukee on April 13, allowed three runs in seven innings of a 4-3 triumph at Philadelphia on Thursday.

Wainwright improved to 3-1 in four starts to go along with a 2.48 earned run average and is 2-1 in three road assignment. In 10 career games (8 starts) against Washington, the right-handed Wainwright is 4-3 with a 3.60 ERA.

The Cardinals, who are just one-half game out first in the Central, lost four of seven regular season matchups with Washington last season, but knocked the Nationals out of the NLDS.