Danny Espinosa cracks a solo home run during the Nationals’ five-run rally in the eighth inning at Wrigley Field. (Jonathan Daniel/Getty Images)

One year ago, Chad Tracy tried to keep his career alive in Japan, halfway out of baseball and halfway around the world. Saturday afternoon, after another crucial hit keyed another delirious rally that led to another Washington Nationals victory, Tracy became, briefly, the No. 2 Twitter trending topic in the United States. “Nice to know,” Tracy said. “I’m not a Twitter guy.”

Two games in, and the Nationals’ season has already reached this level of absurdity? They already believe they can win without offense in innings one through seven? When their all-star offseason acquisition makes his debut and can’t survive four innings?

Why not? The Nationals’ madcap opening weekend continued Saturday afternoon at Wrigley Field with a 7-4 victory over the Chicago Cubs and their flammable bullpen. The Nationals again entered the final innings with a deficit and a dead offense, and again they won.

The Nationals trailed 4-2 in the eighth inning, with two outs and two strikes on Danny Espinosa. Then eight consecutive Nationals hitters reached base, a five-run rally ignited by Espinosa’s solo home run off Kerry Wood, keyed by Tracy’s bases-loaded, two-run, go-ahead single off Carlos Marmol. The comeback bailed out Gio Gonzalez after he allowed four runs in 32 / 3 laborious innings.

“These guys are making me work too hard,” Manager Davey Johnson said, walking down the tunnel back to his office. While Espinosa insisted the Nationals could not rely on late-inning surges, some of Johnson’s players planned to keep making it hard on him.

“We kind of like this,” first baseman Adam LaRoche said. “We perfected it at times last year. So just keep it going.”

Tracy was not the only hero, not even close. After LaRoche struck out three times Thursday in the Nationals’ 2-1 season-opening win, his 9-year-old son, Drake, asked him, “Dad, what were you doing today?” Saturday, LaRoche had his best game as a National, going 4 for 5 with a two-run homer, his first since last April.

The Nationals’ bullpen fired 51 / 3 scoreless, one-hit innings, allowing the offense time to rally. Craig Stammen relieved Gonzalez, escaped a jam and recorded seven outs. Tyler Clippard, Ryan Mattheus and Henry Rodriguez — notching his first save while hitting 101 mph on the stadium radar gun — each followed with a scoreless inning.

“If it wasn’t for the bullpen,” Gonzalez said, “it would’ve been an ugly day.”

“Everybody on the 25-man, everybody’s got their own little role,” Stammen said. “And every single role that they have is just as important as the other one.”

The rally could have died before it even began if not for Espinosa. He fouled off four consecutive two-strike pitches from Wood, waiting for a pitch to drive. On the 10th pitch, Espinosa took a smooth, easy swing and launched a 96-mph fastball over the left field fence, slicing the Cubs’ lead to 4-3 and giving the Nationals hope.

“I was just trying to battle and lay off the tough pitches,” Espinosa said. “The last pitch, I finally got a pitch I could handle and do something with.”

In the end, though, Tracy again provided the fulcrum in a pivotal rally. Thursday, Tracy crushed a two-out double in the ninth inning. Saturday, he came to the plate with the bases loaded, two outs and Marmol, the right-hander he had drilled the double off of, on the mound.

Tracy had spent the game as he always does, trying to manage along with Johnson, envisioning how and when he might come into the game. In the seventh inning, when Johnson double-switched Mark DeRosa out of the game, Tracy sensed he would be pinch-hitting in his spot.

“I played it through my head before I go up there,” Tracy said.

Even though Marmol had just walked Jayson Werth to load the bases, Tracy wanted to stay aggressive. “You can’t wait on him to get to his nasty stuff because you have one at-bat,” Tracy said. “You’re not really trying to feel him out.”

Tracy swung at the first three pitches, fouling all of them away. Down 0-2, he took a ball, fouled away a slider, took another ball. On the at-bat’s seventh pitch, Tracy rolled a single through the right side, scoring Ryan Zimmerman and LaRoche, both of whom had singled.

Zimmerman raised his arms and screamed and LaRoche clapped his hands. On first base stood Tracy, again the improbable star. After playing in Japan last year, a miserable experience, Tracy, 31, signed a minor league contract with the Nationals this winter. He took more at-bats than anyone in spring training, starting slowly before finding his way on to the roster.

“When he came into camp, he’d be the first one to tell you that his chances weren’t great,” LaRoche said. “Whether they were, 50-50, whatever they were, he had to earn everything he got on this club to make this team. We’re glad to have him. He’s going to be a big part of this.”

Less than a week after he secured his place on the Nationals, Tracy has become a part of the team’s fabric. Even with Michael Morse and Rick Ankiel set to return from the disabled list within a week, “Tracy ain’t leaving,” Johnson said Thursday.

“I had to earn it,” Tracy said. “A few guys knew me and played against me, but as far as being a teammate and earning the respect of those guys, I think it took all of spring training.”

Last year, when he left for Japan, Tracy wondered if he would ever play again in the major leagues. This spring, a part of him worried if he may have to find a new line of work. Saturday, he stood in visiting clubhouse at Wrigley Field, surrounded by happy teammates, a hero for one more day.

“You know, you can’t really draw it up like that,” Tracy said. “But it’s been great.”