Adam LaRoche returns to a pleased dugout after hitting a two-run home run in the sixth inning. (Jonathan Newton/The Washington Post)

Baseball seasons bend toward combustion. The days are hot. The losses stack up. By mid-August most every team has become a petri dish of stiff backs, sore knees and strong wills. Inside the Washington Nationals’ clubhouse, Jayson Werth accepts nothing below his particular standard, and Gio Gonzalez, for his class-clown persona, grows protective and ornery every fifth day. The Nationals had barricaded friction below the surface, but on Tuesday night it blew up.

“We’re around each other all day long,” first baseman Adam LaRoche said. “And occasionally some tempers are going to flare.

The trick, upon the inevitable spillover of emotion, is to turn frustration on someone else. The Nationals did against the San Francisco Giants in a 4-2 victory at Nationals Park, weathering both the first-inning shouting match between Gonzalez and Werth and a 77-minute rain delay. The storm knocked Gonzalez out after he pitched four scoreless innings with a stiff back, and the Nationals leaned on five relievers and Adam LaRoche’s two-run homer in the sixth inning.

As midnight approached, the Nationals could spin a convenient and quite likely truthful narrative: They care enough to bicker. Gonzalez and Werth squaring off in the dugout provided a sign of life for an underachieving team that has won four straight.

“Oh, just a little camaraderie going on,” Manager Davey Johnson said. “Spirits are high. I like it. No big deal.”

Gonzalez and Werth provided a quarrelsome sideshow, but neither their spat nor Werth’s two inning-ending strikeouts prevented the Nationals from winning. In the eighth, Werth smacked a leadoff double and then slid home on his bruised right knee, an insurance run scored on Kurt Suzuki’s sac fly. Rafael Soriano handled the ninth for his 30th save, and Tanner Roark paced the bullpen with no earned runs in two innings for his second win.

The root of the Werth-Gonzalez tiff formed in the top of the first. Joaquin Arias flared a hit down the right field line, a likely — but not certain — double. Werth, playing with the sore right knee he sustained sliding into home plate Sunday, ran to scoop up the ball. As Arias hustled to second, Werth spun, double-clutched and lobbed the ball back to the infield.

After a walk to Brandon Belt, Gonzalez induced a bouncer to the right side from Buster Posey. LaRoche shuffled to his right to field the ball and fired to shortstop Ian Desmond. The Nationals had a chance for a double play, but Gonzalez had lingered on the mound. He could only hold up his left hand, warning Desmond not to throw to a barren first base.

Gonzalez escaped the inning with a zero. As the Nationals came off the field, Gonzalez approached Werth and said something. Werth responded. Werth’s effort on Arias’s double may have upset Gonzalez. Gonzalez’s failure to cover first base may have angered Werth. Maybe both.

“Jayson sometimes can get a little vocal,” Johnson said. “He thought Gio was a little late covering first. And he was. But he falls toward third. With a bad back and falling toward third, he couldn’t get over there.”

Werth declined comment, and Gonzalez would not divulge much either.

“It stays between me and Werth,” Gonzalez said.

Whatever the dispute, tempers overflowed in the dugout. Werth barked in Gonzalez’s face as he walked past him on the way to the bat rack. Gonzalez yelled back. Pitching coach Steve McCatty stationed himself in front of Gonzalez and held him back with his left arm.

Werth walked to the end of the dugout with a scowl on his face, turning around after saying a few final words. Gonzalez kept shouting at Werth, trying to push through McCatty. Veteran Scott Hairston rushed between the players. Other teammates looked on. The spat dissipated.

“We just forget about it,” LaRoche said. “That’s the thing where, we’ve got a year where we underachieved and then struggling. . . . Guys are competitive. That’s going to happen. They’ll both be over it tomorrow as so will we.”

Gonzalez had problems to handle other than his argument with Werth. Gonzalez felt his back stiffen “on one pitch,” Gonzalez said. After the top of the second, Gonzalez stretched his back in the Nationals’ dugout, touching his toes and forming a half moon with his torso. McCatty and head athletic trainer Lee Kuntz checked on him. Gonzalez began the top of the third by walking counterpart Madison Bumgarner on four pitches.

“It was a little uncomfortable at the beginning,” Gonzalez said.

Powering through his back issue, Gonzalez ended the fourth with a 94-mph fastball on the black to freeze Brandon Crawford. Desmond led off the bottom of the inning with a double off the right-center field wall, and he scored the game’s first run after Wilson Ramos smacked an RBI grounder off Bumgarner.

Once strong winds blew a mighty rain over Nationals Park, Johnson knew Gonzalez’s day had ended, even if Gonzalez wanted to keep pitching. During the delay, Roark listened to his headphones — Metallica and Linkin Park — and prepared as if he would start.

“It almost kind of feels like two separate games,” Roark said.

In the fifth, with runners on the corners and two outs against Roark, Posey chopped a ball toward shortstop. Desmond charged, and as he stabbed at the ball it scooted under his glove. The third out rolled into center field, and the tying run crossed the plate.

Desmond started the decisive, brief rally with a leadoff single in the sixth. Guillermo Moscoso then fed LaRoche a 1-0 fastball at the letters. LaRoche blasted the pitch off the façade above the home bullpen in right field.

The procession of relievers — Roark to Fernando Abad to Ryan Mattheus to Tyler Clippard to Soriano — kept the Nationals ahead. Tension may mount over the long season, but victory tends to defuse.

“We may be far away right now,” Soriano said. “Right now, we don’t think about that. We think about winning and see what happens.”

Nationals Note:Ramos left the game after the fourth inning after aggravating his left hamstring, the same injury that twice sent him the disabled list earlier this season. Johnson said the injury is not as serious as the previous two setbacks. He labeled Ramos “day-to-day.”