WASHINGTON -- First, David Hernandez enjoyed the unique sensation of working with a four-run lead.
And then, for the first time in 17 starts, the Baltimore Orioles right-hander celebrated a victory.
Backup catcher Craig Tatum had two hits and two RBIs for the Orioles, who improved to 6-17 on the road by winning the opener of this three-game interleague series dubbed "The Battle of the Beltways."
Hernandez (1-5) had lost 11 straight decisions since beating Oakland on Aug. 11, 2009 -- the second-longest dry spell in Orioles history behind Mike Boddicker's 13-game skid (1987-88).
"It feels a lot better than getting a loss, that's for sure," he said. "It's always great when the team gets a victory and I can pitch well enough to get a victory."
In his first seven starts, the Orioles scored a total of seven runs while Hernandez was in the game. In this one, they went up 2-0 in the second inning on Jones' first homer since April 24, then made it 4-0 in the third.
"It definitely helped getting a two-spot in the second inning and then adding another two runs," Hernandez said. "I was able to relax."
Hernandez had a no-hitter until Nationals pitcher Miguel Batista singled with two outs in the fifth. It was Batista's first hit since Aug. 9, 2006, when he doubled against San Francisco for Arizona. Since then, he had gone 0 for 22.
"My hits are like comets," Batista said. "They happen every five or four years."
Hernandez walked five, including two straight with one out in the sixth that led to his departure after 105 pitches.
"He gave us what he had," Orioles manager Dave Trembley said. "Maybe this will get him on a roll."
Willie Harris homered for the Nationals, who have lost seven of eight to fall under .500 for the first time since April 15.
"I don't think we're in a rut. We're just not scoring big runs when we need to," Harris said. "... We're on a little skid, but I don't think it's anything serious, anything to worry about."
The Orioles made it 5-3 in the eighth when Tatum walked and scored on a two-out single by Corey Patterson.
Alfredo Simon, the fifth Baltimore pitcher, worked the ninth to complete the five-hitter and earn his sixth save.
Nationals starter Scott Olsen (2-2) allowed four runs and six hits in three innings before leaving with left shoulder tightness. He gave up as many runs in this game as he did in his last five starts combined.
"He was not feeling good from the bullpen on, and just tightness in his shoulder," Washington manager Jim Riggleman said. "He was trying to battle through and he gave us everything he had. A very gutty performance."
The Orioles went up 2-0 in the second inning when Luke Scott hit a leadoff single and Jones followed with his fourth home run.
"That felt good. It's been a struggle," Jones said. "But the name of the game is keep swinging the bat, so I kept swinging it."
Jones left in the fourth inning with a leg cramp, but he said it soon went away.
In the top of the third, a single and two walks loaded the bases for Tatum, who hit a two-run single up the middle. Tatum was subbing for injured Matt Wieters, who sat out with a sore right knee.
Wieters was rested after fouling a ball off his knee in Thursday's game against Texas. He expects to play Saturday. ... In his 10th game since being summoned from the minors, Patterson recorded this third stolen base -- taking over the team lead. But he was caught leaning too far off third base in the fourth inning and tagged out in a rundown. ... The Orioles took a 13-12 lead in the series, which began in 2006. ... Washington's Adam Dunn walked twice, but his nine-game hitting streak ended. ... Riggleman called on P Livan Hernandez to pinch hit in the third inning. He struck out.