WASHINGTON -- Stephen Strasburg took a swing and looked in amazement as the baseball carried over the left-field wall.
If Strasburg's first major league homer came as a surprise, his performance on the mound did not. With Strasburg leading the way, the Washington Nationals beat the Baltimore Orioles 9-3 Sunday to avert a three-game sweep.
In addition to his 2-for-2 performance at the plate, Strasburg (4-1) struck out eight in five innings before being lifted by manager Davey Johnson, who said the pitcher mentioned tightness in his biceps.
"I don't care who it was, if I find out they have tightness, they're out," Johnson said. "I talked to him later in the game. He said it relaxed a bit and was a lot better. I'm not as concerned when it's in the biceps."
Strasburg attributed the soreness in part to working too hard in the days following his previous start.
"The biceps is fine," he said. "It's just throwing a lot of pitches early, then we put up a lot of runs and stuff. I just got a little tired, got a little tight, but that's nothing different than any other outing."
Strasburg sent an 0-2 pitch from Wei-Yin Chen into the Baltimore bullpen in the fourth inning to put the Nationals ahead 5-3. After dusting off his home run trot and returning to the dugout, he responded to a curtain call by waving to the crowd of 41,918.
"Shocking, that's for sure," Strasburg said of his clout. "I feel like in (batting practice) I have to swing a lot harder to hit it out. I just somehow ran into one."
He was almost embarrassed about his trip around the bases and subsequent climb up the dugout steps.
"I'm not big for going out there and showboating," Strasburg said. "It was great, but I know my place. I'm not a real hitter out there so I'm not going to go out there and act like I do it all the time."
The hard-throwing Strasburg had five hits in 40 big league at-bats before Sunday. He singled and scored in the third inning, then followed a shot by Jesus Flores with one of his own in the fourth.
"I didn't expect Stras to hit a breaking ball," Johnson said. "He doesn't usually see breaking balls. (Third base coach) Bo Porter came in after and said we found a left fielder."
Known more for his pitching than his hitting, Strasburg excelled at both. The right-hander allowed three runs, one earned, four hits and a walk in his first career appearance against Baltimore. He retired the last 10 batters he faced.
Since returning from elbow ligament replacement surgery last September, Strasburg is 5-2 with a 1.99 ERA in 14 starts.
Danny Espinosa also homered, and Bryce Harper drove in two runs and scored three for the Nationals.
Chen (4-1) yielded six runs and eight hits in 4 1-3 innings and absorbed his first major league loss. The Taiwan native was vying to become the first Baltimore starter to begin his Orioles career with five straight wins since Jimmy Key in 1997.
"This is baseball. Sometimes you have a good day, sometimes you have a bad day," Chen said through a translator. "Definitely, I had a terrible start today."
The loss ended Baltimore's five-game winning streak and nine-game road run. The Orioles scored the game's first three runs but got only two hits after the second inning – both in the ninth.
"If you came in today thinking you'd get their starting pitcher out of the game after five innings, you'd like your chances," manager Buck Showalter said
Baltimore went up 1-0 in the first when Xavier Avery walked, advanced on a fly ball and scored on a single by Nick Markakis.
The Orioles added a pair of unearned runs in the second after Harper drifted from center to left field to chase down a wind-blown fly ball, then dropped it. Robert Andino drove in a run with a groundout and Avery added an RBI single before Strasburg struck out J.J. Hardy with two outs and runners on second and third.
Harper made amends in a three-run third. Strasburg singled, Espinosa doubled and Harper hit a liner to right that a diving Markakis gloved but lost when he hit the ground. The triple scored two runs, and Harper scored on a groundout by Ian Desmond.
Flores gave Washington a 4-3 lead with his first homer since Aug. 18, and that only served as a prelude to Strasburg's drive.
Desmond chased Chen with an RBI single in the fifth, and Espinosa homered with a runner on during a three-run eighth.
NOTES: Orioles C Matt Wieters, who had the day off after a night game, will have to wait until Monday to try to snap an 0-fror-18 slump. ... Tommy Hunter (2-2) takes the mound for Baltimore on Monday night in the opener of a three-game series against visiting Boston. ... Gio Gonzalez vies for his sixth win when the Nationals open a nine-game road trip Monday in Philadelphia. ... Avery got his first major league stolen base.