ST. PETERSBURG, Fla. -- Ben Zobrist started the season as the Rays' super sub. Now he may have won a starting spot at second base.
"He obviously does not want to be a part timer," Tampa Bay manager Joe Maddon said of Zobrist, who has played second on a regular basis since Akinori Iwamura was lost for the season with a left knee injury on May 24.
Carlos Pena hit his 20th home run for Tampa Bay. The defending AL champion Rays moved two games over .500 for the first time this season.
"You've got to keep pushing, pushing, pushing," Maddon said.
Andy Sonnanstine (5-6), who retired 15 batters in a row at one point, gave up three runs and six hits over 7 1/3 innings.
Ryan Zimmerman hit his 12th homer and drove in two runs for the Nationals.
Washington starter Jordan Zimmermann allowed one run and four hits in five innings. He struck out six and left with a 2-1 lead.
"I made some good pitches when I had to," Zimmermann said. "I had to battle pretty much every inning. I'd either walk a guy or they'd get a leadoff hit. It was a constant battle the five innings."
Zobrist followed with a three-run shot -- he has a career-high 13 homers this year, including five in his past 11 games.
"I feel good about playing anywhere," Zobrist said. "I like being in the lineup, so if I can get in there wherever it is, I'm not going to be picky. I'm just feeling great about how the season has gone so far."
After Pat Burrell walked, Gross extended the Rays' advantage to 6-2 with a two-run homer. Bergmann gave up five runs without recording an out.
"I didn't have a great sinker. I was trying to throw a strike instead of a good pitch and I think I made a mistake in that," Bergmann said.
Longoria's two-run double later in the inning against Jesus Colome made it 8-2.
The Rays have scored five or more runs in an inning 17 times this season, the most in the majors.
Zimmerman hit a solo homer in the first. The Nationals loaded the bases with no outs in the third, and Zimmerman had an RBI grounder.
"That was a key for us," Nationals manager Manny Acta said of the third. "I thought that was an inning where we could have scored more runs and we couldn't do much. We felt we had Andy on the ropes, but we couldn't deliver a knockout punch."
Pena homered in the fourth.
Longoria, who returned to the lineup Monday after being limited to pinch-hitting because of tightness in his left hamstring for six games, went 2 for 4. He has three hits in his last 26 at-bats, and struck out in the first and third innings with a runner in scoring position.
Rays reliever Jason Isringhausen left with pain in his right elbow after throwing a pitch in the ninth. He had surgery on the elbow last September.
"I don't know what level, but there is concern," Maddon said.
Isringhausen underwent tests after the game. The Rays said there would be more information on the injury Sunday.
Iwamura will undergo surgery to repair a torn ligament in his knee on June 22. ... Nationals OF Josh Willingham was placed on the bereavement list after his younger brother was killed in a car accident Friday night. ... Sonnanstine has allowed 13 homers in his last seven starts, including five over the past two outings. ... Tropicana Field (32 games) and Yankee Stadium (31 games) are the only stadiums in the majors where at least one homer has been hit in every game this season.