Adam LaRoche, right, is congratulated after one of his two home runs against the Rockies. LaRoche leads the team with 15 home runs. (Justin Edmonds/GETTY IMAGES)

The numbers in the Washington Nationals’ box score Tuesday night looked like a misprint, or some delightful hallucination. These Nationals typically score runs by the thimble. They scored by the wheelbarrow Tuesday. Against the Colorado Rockies’ beleaguered pitching staff, they stacked hits and homers like cordwood. They peppered line drives. Every flare found turf. They pulled the handle of a slot machine, and it would not stop spitting quarters.

The Nationals whacked 21 hits in their 12-5 thumping of the Rockies in the thin air at Coors Field, tying the most for the franchise since it relocated to Washington in 2005. They mashed four home runs and seven doubles, and those 11 extra-base hits were a new high. They scored eight runs off one relief pitcher. Their 12 runs were the most they have scored under Manager Davey Johnson and they most they have scored, period, since May 20, 2011, a span of 189 games.

“We’ve been waiting on this all year,” first baseman Adam LaRoche said. “We’ve known what this offense can do and just haven’t seen it. It was nice to see the potential of this lineup.”

The angst about the Nationals’ anemic offense had become so heated that Johnson found himself supporting hitting coach Rick Eckstein before the game. One game cured all ills and relieved any concerns.

“My hitting coach is a genius,” Johnson said. “What can I say?”

Ian Desmond went 4 for 5 with three doubles. Michael Morse went 4 for 5 with one double. Adam LaRoche drilled two homers, his first two opposite field home runs this year, to give him a team-high 15. Tyler Moore clobbered a three-run homer. Every Nationals starter, including pitcher Gio Gonzalez, swatted at least one hit. One more, Mark DeRosa, came off the bench and ripped a double, which raised his batting average from .081 to .105.

“Even DeRo got off the Interstate,” Johnson said.

Ryan Zimmerman went 3 for 4, rolling a single into right field for the 1,000th hit of his career and crushing his first home run in 70 at-bats, a missile into the left field seats. Even more than their crooked run total, Zimmerman’s breakout may have been the most encouraging aspect of their beatdown of the Rockies.

Since Zimmerman received a cortisone shot before Sunday’s game, he is 6 for 12 with two doubles and a homer. The procedure has allowed him to swing freely and find the form that makes him one of the league’s most dangerous hitters and the cornerstone of the Nationals’ lineup.

“It feels better,” Zimmerman said. “I think I can do things and swing and prepare like I’ve always swung before. It just freed it up a little and let me do things like I’ve always done. It’s hard to try and make adjustments and do things the way you don’t normally do them and be successful.”

Gonzalez notched his 10th win, tying him for second in the National League. He allowed five runs, four earned, over six innings. He struck out seven and allowed two solo home runs, only the second and third homers he has yielded over 90 2/3 innings, the product of high altitude and pumping strikes with a huge lead.

“You don’t want to fall behind, give them a chance to start to come back,” Gonzalez said. “I was just trying to do my best to keep pounding. That’s what each one of the guys kept saying — continue to pound the strike zone, get us back in here as quick as possible.”

Gonzalez was not his usual, dominant self. For once, the Nationals starter did not need to be dominant for them to win. The main requirement Tuesday night was one workable arm and a pulse.

“There’s too many times when they’ve given up two or three and lost,” Zimmerman said. “We owe them a lot, to say the least.”

Before Tuesday night, the Nationals had scored more than seven runs twice all season, never more than nine. Since Johnson took over precisely one year ago, they had scored in double digits just once. And then, they broke out.

“For us to kind of continue to grow and get better, we can use this as kind of a springboard I think,” Zimmerman said.

The Nationals did their damage partly against starter Christian Friedrich, a rookie left-hander who entered with a 5.65 ERA, and mostly against right-handed reliever Guillermo Moscoso.

It was still a close game in the fifth inning. The Nationals took a 4-3 lead in the fourth when Gonzalez poked a single to center field. Before the at-bat, he said, Stephen Strasburg told him to reduce his swing, just try to make contact.

With one out in the fifth, Rockies Manager Jim Tracy pulled Friedrich for Moscoso. A tight game turned into Nationals batting practice.

Zimmerman’s single seemed innocent enough. Morse singled, too, and then LaRoche walked. You can lose track of turning points in a blowout such as this one, but Desmond provided it with a clutch, tough at-bat.

Desmond fell behind Moscoso, 0-2. He fouled four pitches, including one foul tip that barely popped out of catcher Wilin Rosario’s mitt. On the eighth pitch of the at-bat, Desmond smashed a two-run, bases-loaded double off the left field fence. The most crucial at-bat of the night gave the Nationals a 6-3 lead.

“It was awesome,” LaRoche said. “That’s what I told him. Obviously, he sparked that inning.”

Moore sealed it with a home run, a blast more the three-quarters of the way up the seats in left field. In the dugout, LaRoche embraced him.

“He said something like, ‘You didn’t have to show me up like that,’ ” Moore said. “But he ended up hitting another one, so he showed me up big time.”

The Nationals pushed across five runs in the fifth inning. They had scored five runs in an entire game once since June 14. The numbers kept piling up. In six innings, the Nationals matched their combined run total from their previous five games. They battered Moscoso for eight runs in 1 2/3 innings; they had scored seven runs in the previous four runs combined.

“We had good at-bats today,” Zimmerman said. “We had good pitches to hit, and we hit ’em. We took a lot of pitches that we’ve been swinging at in the past, which are more pitcher’s pitches. When you take those and those are balls, now you’re set up to kind of hit your pitch. We did tonight. We didn’t miss them when we got the chance.”

Sometimes, like over the weekend in Baltimore, five runs constitutes an entire series for the Nationals. For one loopy night, it was only the beginning.