CHICAGO — Sunday afternoon, the Washington Nationals copied the formula that gave them two victories to start this season, except for the important part. Their offense stalled. Their pitching, in this case seven stellar innings from Jordan Zimmermann, kept them in the game. They staggered the Chicago Cubs in the final innings. They just never completed the comeback.

In a 4-3 loss before 31,973 at Wrigley Field, the Nationals nearly shocked the Cubs again after Adam LaRoche drilled a two-out home run in the top of the ninth, an offensive spasm after another punchless beginning. The Nationals wasted Zimmermann’s dominance and mostly kept alive concerns about their ability to score runs. Still, even as right-hander Jeff Samardzija mowed them down, the Nationals had conditioned themselves to believe they would somehow win.

“All of us thought we had a chance,” LaRoche said. “Anything can happen in baseball. We were putting up a fight. Just too little, too late.”

While cleanup hitter Michael Morse continued rehab in the minors from a strained muscle in his back, the Nationals managed four hits and struck out eight times against Samardzija, a converted reliever who came within one out of a complete game in his sixth career start.

After Ian Desmond led off the game with a double, Samardzija retired 15 consecutive hitters. With the Cubs’ three starting pitchers on the mound in the season-opening series, the Nationals scored five runs in 22¹ / ₃ innings. During the first seven innings in their opening series, the Nationals went 9 for 72 (.125) with four walks.

“I think it’s too early to worry about that,” LaRoche said. “I think that’s just more the way it’s been going.”

They could find plenty of culprits. Ryan Zimmerman, robbed of two homers by the wind in the opener, went 0 for 4, dropping to 1 for 11. Chad Tracy, the off-the-bench hero in two wins, struck out in his eighth-inning pinch-hit appearance. Jayson Werth went 0 for 3 with a strikeout and a ninth-inning walk Sunday, making him hitless in 10 at-bats with five strikeouts to start his second Nationals season.

Werth carried confidence in his swing out of spring training, and his disappointing results haven’t changed that. Werth drew three walks, including one Sunday with two outs in the ninth off Carlos Marmol that set up Xavier Nady’s game-ending pop-up. He narrowly missed his first hit Sunday when third baseman Ian Stewart made a diving stop and strong throw.

“I worked some walks in some tights spots against some pretty good pitchers,” Werth said. “I swung the bat good the first day. I couldn’t come up with anything. Just part of the game. I feel good.”

The offensive rut forced Zimmermann to face the same fate he did so many times last season, an outstanding start foiled by not enough run support. The Nationals scored 3.2 runs per game when Zimmermann started last year. Sunday, when he allowed two runs, only one earned, on six hits and no walks over seven innings, they managed a lonely one until the ninth.