Nationals pitcher Stephen Strasburg gave up two runs over seven innings of work Friday night in an 8-4 victory over the Diamondbacks. (Matt York/AP)

Stephen Strasburg swapped his exasperating innings limit of 2012 for a 2013 series of minor calamities, controversies and oddities, some within his control and some not. What remained was the gnawing sense that his frequent excellence remains a tease for what he can become. “He’s good,” catcher Wilson Ramos said. “And he will be better.”

The Washington Nationals allowed Strasburg to keep pitching until the end this year, and his season concluded Friday night at Chase Field with an 8-4 victory over the Arizona Diamondbacks. Strasburg allowed two runs over seven innings and finished his season by retiring 13 of the final 15 batters he faced. He found early trouble, righted himself and cruised to the end.

At age 25, even with a brief trip to the disabled list, Strasburg submitted an impressive season. Strasburg went 8-9, pitched 183 innings – 232 / 3 more than his truncated 2012 season — and punched up a 3.00 ERA with 191 strikeouts, 56 walks and 136 hits allowed. His fourth big league season was his first full season. It still felt like a transition episode, the bridge between his shutdown and the full-blown ace he can become.

“I still think Stephen’s got a long way to go,” Nationals right fielder Jayson Werth said. “He’s got a while until he’ll reach his ceiling. But he’s young, he’s still learning. But this year’s been good for him. I think it’s been a challenging year, it’s been a trying year for him, and it probably didn’t go exactly the way he wanted it to. But he pitched good. He grew up a lot throughout the year, and I think it’s definitely something that he can build on.”

Werth, who blasted a game-breaking, three-run homer, was told Strasburg’s statistics for the season.

“Yeah, pretty rough on him, I guess,” Werth said, smiling.

The thing is, there may be no one tougher on Strasburg than himself. That, too, is one area in which Strasburg improved.

“I put more pressure on myself than anybody,” Strasburg said. “I think I have to step back a few times and not be so hard on myself. Because I honestly do expect to throw a no-hitter out there every time. It still hasn’t happened, but I expect it to.”

Strasburg received some of the worst run support in the majors, but the Nationals’ lineup bolstered him Friday night against Diamondbacks lefty Patrick Corbin. Strasburg fell behind 2-0 in the third. Bryce Harper smashed an RBI double in the fourth. In the fifth, Werth provided the most important and impressive blow. He broke a 2-2 tie with a three-run homer off the face of the upper deck in left, his 25th of the season. Ramos smashed a towering three-run shot of his own to seal the game in the eighth.

The Nationals’ outburst helped Strasburg cruise to his eighth win. He entered the season with the ambition of becoming the staff workhorse, and he took another step Friday night. He pitched at least seven innings for the 16th time in his 30 starts. Last season, Strasburg pitched seven innings only five times in 28 starts.

“The one thing I did a good job improving on from the beginning of the season was that the things that happened that were unexpected, I tried not to let that affect me as much and carry over to the next pitch,” Strasburg said. “Obviously, there were a lot of crazy things that happened this year for me and for this team. That’s one thing we learned as a group: It all doesn’t matter. It’s all about how you respond to it.”

The Nationals shut Strasburg down in 2012 to ensure he would stay healthy, and for the most part he avoided injury. Strasburg missed two starts in June with a lat strain and skipped another in September with irritation in his forearm.

He also dealt with other, self-inflicted hurdles. Early this season, teammates and his manager openly asked for better mound presence. In one start this month, he balked in two runs. He exacted revenge by hitting an Atlanta Brave with a pitch in defense of Harper, and then he got ejected the next inning when he twice threw behind another to push in a run.

“When he’s thinking too much, he’s not the guy we know he can be,” Ramos said. “If he goes out there and doesn’t think anything, just throws the ball, he will be fine. That’s what he needs to do. He’s got really, really good stuff and pretty good command. He can do anything he wants.”

During an April start, Strasburg imploded after Ryan Zimmerman committed a crucial error. He slumped his shoulders and stared at the dirt. Afterward, Ramos told him, “You have to fight.” Johnson implored him to show better body language. Strasburg listened. The problem disappeared.

“Now, he’s better,” Ramos said. “He’s not doing that. After he throws a walk, he puts his head down - he’s not doing that. He’s better.”

Strasburg showed Friday night he could leave behind a difficult moment. Leading off the third, Strasburg walked No. 8 hitter Didi Gregorius. Corbin tried to bunt and fouled his way to a 1-2 count. As Corbin squared, Strasburg twirled a low-and-inside curveball that hit Corbin in the shin. Rather than taking the out, he had put two runners on base with no outs.

Adam Eaton and Gerrardo Parra each poked singles, which sent the Diamondbacks ahead, 1-0. Strasburg fought out of the jam. Paul Goldschmidt, possibly the National League’s Most Valuable Player, grounded into a 5-4-3 double play to score the second run. Strasburg walked Martin Prado, but he escaped the inning on Aaron Hill’s foul pop-up.

“He’s much calmer,” Johnson said. “He’s not letting the little things bother him anymore. He’s right where he needs to be.”

After Strasburg’s rocky inning, he allowed only two more Diamondbacks to reach base. Strasburg filled the strike zone with fastballs between 93 and 96 mph. He relied on his curveball as his primary offspeed pitch and sprinkled in his change-up.

Strasburg’s primary aim Friday was keeping Arizona baserunners in check. For the first time all season, Ramos said, Strasburg tried to pick off runners without being prompted by a sign.

“I didn’t really care how the game went today, I just wanted to make sure they weren’t getting free bases,” Strasburg said. “And I was able to do that. I know that if I work on that, the little things, it’s really going to save me a lot of runs.”

Strasburg received help in the first inning from what may have been Zimmerman’s best play all season. Eaton led off with a sharp ground down the left field line. The ball appeared already to be past Zimmerman when he dove to his right. Somehow, he snatched the ball with a backhand. He rose to his feet and offered an answer to anyone still wondering about his arm strength. Off his back foot, Zimmerman ripped a laser across the diamond for the out.

After Eaton lined Strasburg’s 101st pitch to Harper for the final out of the seventh, Strasburg walked off the mound and into the dugout, stone-faced as ever. Johnson shook his hand and patted him on the back. Strasburg walked down the dugout, a good season behind him and even better ones likely ahead.

“He’s got a really high ceiling,” Werth said. “I think everybody knows that. Just the time I’ve spent with him, playing with him, he’s got a long way to go to reach what he’s capable of doing, but what he did this year was great. He pitched good. There’s a lot more in the tank.”