Strasburg (1-1) started for the first time since April 13. He had been sidelined with right shoulder inflammation.
Anthony Santander's leadoff single in the second was the only hit allowed by Strasburg, who walked four and struck out four in 5 1/3 scoreless innings. He threw 72 pitches and picked up his first win in a regular-season game since Sept. 26, 2019. Strasburg won two games in the 2019 World Series, including Game 6, to earn MVP honors.
"It's not where I want it to be, but it's a step in the right direction," Strasburg said. "Execution standpoint, there's definitely some room for improvement.
"It's still only May. I feel good coming out of the start, take what I can from it and get ready for the next one."
When Strasburg departed, the crowd of 14,369 at Nationals Park applauded heartily. It was the first game played with an increased capacity of 36 percent. Full capacity will be permitted on June 10.
"I think not having it for so long, you take it for granted," Strasburg said of the fans. "You really rely on that. You get the fans into the game, and it gives you that extra boost. The atmosphere changes so much, and we really appreciate it as players."
Strasburg made one injury rehabilitation start for Triple-A Rochester, allowing two hits over 4 1/3 scoreless innings on May 16.
"We want him to get as many outs as he can for as long as he possibly can," Nationals manager Davey Martinez said before the game. "I don't want to put any limitations on him and get as many outs as he possibly can and hopefully keep us in the ballgame."
To make room for Strasburg on the roster, Washington optioned right-handed pitcher Kyle McGowin to Rochester.
Martinez also said that right-handed pitchers Erick Fedde and Tanner Rainey, who were placed on the COVID-19 injured list on Tuesday, remain in quarantine in Chicago after Washington played the Cubs. Martinez said he doesn't know when the pitchers will return.
The Associated Press contributed to this report.