The Nationals stole four bases on Lincecum, twice when the runner had such a huge jump there was no reason for catcher Bengie Molina to even attempt a throw.
Three of those swipes came during a three-run rally in the top of the fifth, when Lincecum issued two of his five walks and hit a batter. The Nationals turned Ian Desmond's chip shot of a single into a pair of runs and Lincecum knew where the blame lay.
"It's rhythm and timing," he said. "Those are the keys for me. I had guys running all over me and I was walking guys. That doesn't help my cause. I have to work on holding runners, and it's more being focused on every pitch."
Lincecum (5-1) lost in the month of May for the first time in his career as he lasted a season-worst 4 2/3 innings, giving up six runs on six hits. He struck out five.
Lincecum has allowed 11 runs over his last two starts after giving up 11 over his first eight.
"There's no question he's having trouble with the command of his fastball," Giants manager Bruce Bochy said. "He was out of sync and he lost focus with runners on base. He's just going through a stretch where he's struggling."
Ten short days ago, Lincecum was the proud owner of a 1.76 ERA. After Wednesday's little setback, it's at 3.00 for the season.
A short history lesson about Lincecum: After 100 appearances, 99 starts, his career ERA stands at 2.91, mostly due to the 11 runs he's allowed over the last 9 2/3 innings. He's never finished a season with an ERA over 2.62. Perhaps it's time he cut himself some slack.
"I don't want to show the frustration," he said. "But then you see those patterns develop again and again over the last two outings and it starts to manifest itself and I start overthinking."
At the same time, Lincecum knows what it takes to be successful, and the fire that stokes his competitive nature will ultimately lead him to some answers.
"The biggest issue is his command," Bochy said. "It's getting away from him. We have a lot of work to do. His next bullpen will be important."
What is not a source of complaint is a blister problem that seems to have gone viral. He developed one during Spring Training and has dealt with them through his entire professional career.
"It's a non-issue," Bochy said. "We wouldn't pitch a guy with a blister. He's fine and he's going to make his next start."
Lincecum confirmed the non-issue. "It's nothing," he said. "I go through them all the time. It had nothing to do with anything."
In case you're looking for a premier matchup, his next scheduled start comes Monday, when he faces the Colorado Rockies and their bright pitching star Ubaldo Jimenez, who won his league-leading ninth game Wednesday night.
On Wednesday, Juan Uribe hit a home run, Pablo Sandoval doubled home a run and Aaron Rowand, who had two hits, scored on a throwing error for the Giants, who lost their sixth in the last seven games.
Andres Torres tripled and scored a run and has a .362 batting average (17-for-47) over his last 13 games.
Nationals starter Luis Atilano took a one-hitter into the fifth inning and pitched well enough to win for the fourth time in five decisions.