Nationals 2, Cardinals 1: Jayson Werth sent a solo home run into the bullpen in left-center field to keep host Washington alive in the National League Division Series.

Werth saw 12 pitches and fouled off seven from Lance Lynn (1-1) before getting one he could handle. He blasted the 13th offering, a belt-high 96 mph fastball, on a line over the fence to force a deciding Game 5 on Friday night.

Ross Detwiler allowed three hits and an unearned run in six innings before handing it off to the bullpen. Jordan Zimmerman and Tyler Clippard each struck out the side in the seventh and eighth, respectively, and Drew Storen (1-0) punched out two in the ninth to earn the win.

Adam LaRoche got Washington on the board in the second inning with a solo home run. The slugger got underneath a 3-2 sinker from Kyle Lohse and blasted it onto the batter’s eye beyond the center field fence.

The Cardinals evened it on an unearned run in the third. Pete Kozma led off with a walk, moved up on Lohse’s sacrifice and scampered to third safely on shortstop Ian Desmond’s error before scoring on Carlos Beltran’s sacrifice fly to center.

Desmond saved a run in the ninth inning, racing back to snag a pop up near the foul line in shallow left field and end the inning.

GAME NOTEBOOK: The teams combined for six hits in the contest. … Lohse struck out five and was charged with one run on two hits in seven innings. … Nationals CF Bryce Harper went 0-for-3 and is 1-for-18 in the series. … Washington LHP Gio Gonzalez will get the start in Game 5 opposite Cardinals RHP Adam Wainwright.