WASHINGTON — Stephen Strasburg winced and, no doubt, so did everyone else who roots for the Washington Nationals.

The Washington ace felt a pinch in the back of his right elbow in the third inning and was forced to make an early exit Wednesday night in his first start since returning from the disabled list.

With a stadium full of teammates and fans wondering what went wrong, the NL East leaders went on to defeat Atlanta 5-4 in 11 innings.

After the game ended well past midnight, the Nationals said Strasburg would get an MRI. They didn’t elaborate on the severity of his injury.

“He had good command,” manager Dusty Baker said. “Usually if something’s wrong you don’t have command. So we’re hoping that it’s something minor, but we’ll find out tomorrow.”

Strasburg had been out since Aug. 17 because of soreness in the same elbow. The right-hander left after 2 1/3 innings, allowing a run on two hits.

“He did everything that was asked of him (before the start),” Baker said. “He was cleared. He wasn’t trying to be a hero. He said he felt fine, but a lot of times you really don’t know until you get into the action.”

Strasburg wasn’t in the clubhouse after the game.

“He didn’t stick around because he’s just both frustrated and upset,” Baker said.

With Braves pitcher Mike Foltynewicz attempting to bunt after Dansby Swanson’s leadoff double, Strasburg’s 0-2 pitch sailed high.

Strasburg grimaced, walked around the mound and then threw another pitch, retiring Foltynewicz.

Washington’s trainer came out and Strasburg departed, covering his mouth with his glove as he reached the dugout.

Strasburg struck out four and walked none. He threw 42 pitches.

“I felt very bad for him,” catcher Ramos said. “He was throwing such a good game. He was locating his pitches very well. His velocity was very good.”

Before going on the disabled list, he allowed 19 runs over his final three starts, including nine in 1 2/3 innings against Colorado last time out.

Strasburg started out 13-0 this season, and went into this game with a 15-4 record.

The 28-year-old Strasburg made his big league debut in 2010 but needed Tommy John surgery later that season.

Earlier this year, the two-time All-Star signed a $175 million, seven-year contract that goes into effect next season.

Jayson Werth drew a leadoff walk in the 11th and Daniel Murphy followed with a double off Jed Bradley (1-1). After Bryce Harper was intentionally walked to load the bases, Wilson Ramos singled off Brandon Cunniff to win it.

Mat Latos (1-0 with Washington), the 10th Nationals pitcher, got one out for the win.

Atlanta’s Jace Peterson and Washington’s Anthony Rendon traded RBI singles in the 10th.

Swanson homered for the second straight game, this time sending one over the fence following Tuesday night’s inside-the-park home run.

The rookie said he was getting a lot of playful kidding for his first career homer “being an inside-the-park, so I figured this one would be a bit easier on my psyche.”

Murphy’s two-run single in the seventh tied the score at 3 and gave him 100 RBIs for the season.

The start of the game was delayed 57 minutes, though it ultimately only rained lightly during the early portion of the game.

CENTURY MARK

Murphy posted the sixth 100-RBI season in Nationals’ history (2005-present) and the first since Adam LaRoche had 100 in 2012.

STREAKING

Atlanta’s Ender Inciarte extended his hitting streak to 18 games with an 11th-inning single, and Freddie Freeman upped his string to 14 games.

TRAINER’S ROOM

Nationals: The team reinstated INF Stephen Drew, who missed 40 games due to vertigo-like symptoms.

UP NEXT

Braves: RHP Julio Tehran (5-9, 3.01) starts when the Braves open a three-game series Friday against the Mets. He has allowed two runs over 13 innings while winning his last two starts.

Nationals: RHP A.J. Cole (1-1, 3.86) makes his fourth start of the season when the Nationals host the Phillies on Thursday. Last time out, Cole allowed a run on three hits over six innings to beat the Mets for his first major league win.