OAKLAND, Calif. -- Having discovered his power stroke at the Oakland Coliseum, Athletics catcher John Jaso was more impressed by the ball he hit that didn't leave the park than he was by his second home run in as many days.
That might be because it came in the 10th inning and gave Oakland its third walk-off win of the season.
Jaso, who had not hit a home run in Oakland until his solo shot in Friday's 8-0 win, also homered in the third before delivering the fourth game-ending hit of his career.
"It's funny because I thought that last ball I hit I hit harder than the other two and it hung up for some reason," Jaso said. "I don't know if the wind shifted, but I thought I hit it harder than the other two."
After being limited to two hits over the first eight innings, the A's scored twice in the ninth off Nationals closer Rafael Soriano to force extras and storm back for their third walk-off win this season.
Alberto Callaspo singled off reliever Drew Storen (2-1) to lead off the 10th before Punto replaced him at first. Storen retired Eric Sogard and Derek Norris before Jaso hit a towering fly ball that ricocheted off the scoreboard in right field as Punto rounded the bases and scored.
"Sometimes certain guys come up key in games when you don't get many hits," Oakland manager Bob Melvin said. "[Jaso] did most of the damage. When you get down to those situations, it just becomes a grind."
The Nationals were three outs from winning and had their rock-solid closer on the mound before Oakland greeted Soriano with three consecutive hits to open the ninth.
"Going into the ninth with a two-run lead and a guy that hasn't given up a run in 25 innings and it doesn't happen for you, it's disappointing," Washington manager Matt Williams said. "That's baseball."
It was Soriano's first blown save since Aug. 17, 2013, and ended his career-high streak of 25 consecutive scoreless innings.
That spoiled a stellar outing by Washington starter Tanner Roark.
Coming off the worst start of his season, Roark was masterful while shutting down the A's offense. He allowed two hits over 7T innings, struck out five and didn't walk a batter. He gave up Jaso's two-out home run in the third before retiring the next 13.
The Nationals backed him with just enough offense until the bullpen broke down.
Danny Espinosa hit a towering home run off Oakland starter Sonny Gray with one out in the third to give the Nats an early lead. Zach Walters and Denard Span followed with singles before Kevin Frandsen lined a two-run double to the gap in left-center to make it 3-0.
Jaso's two-out home run off Roark in the bottom of the third trimmed Washington's lead to 3-1.
"It's strange how a pitcher can get on a roll like [Roark] did and everything we put in play was caught," Jaso said. "Those kind of days, that's when you want to get into the bullpen and change the momentum."
Roark left with two outs in the eighth after a throwing error by Espinosa allowed Josh Reddick to take third. Roark fielded Sogard's grounder cleanly, but his throw to first hit Reddick in the back of the helmet and ricocheted near the Nationals dugout.
Tyler Clippard replaced Roark and retired pinch hitter Derek Norris before the A's rallied for the tying runs off Soriano.
Sean Doolittle (1-2) pitched one inning for the win to help Oakland overcome an uneven outing by Gray.
Gray, the AL pitcher of the month in April, struck out three and walked two. He allowed six hits over seven innings and gave up all of Washington's runs in the third
Nationals first baseman Adam LaRoche (quad strain) is headed for the disabled list after aggravating the injury on Friday. ... Injured slugger Ryan Zimmerman (right thumb fracture) has not yet resumed hitting and is scheduled to have another X-ray on Sunday. ... Oakland LHP Scott Kazmir (4-1) pitches the series finale after taking the loss in his previous outing. ... Former A's starter Gio Gonzalez (3-2) goes for Washington. Gonzalez won 15 and 16 games for Oakland in 2010 and 2011, respectively.