WASHINGTON -- Mired in last place in the NL East, the Washington Nationals are still fighting for every win they can get.

Alfonso Soriano hit a two-run homer and rookie Ryan Zimmerman's bases-loaded walk in the 11th inning lifted the Nationals over the Arizona Diamondbacks 7-6 Saturday for their first back-to-back wins in franchise history when trailing by two or more runs entering the ninth.

The Nationals trailed 6-1 heading into the bottom of the eighth.

"It feels good to win two games of any kind," manager Frank Robinson said. "It was especially nice for the kids that went out there and did a job for me on the mound and kept us in the ballgame. We're not going to pack it in until the season's over."

Bernie Castro led off the bottom half of the 11th with a walk against Arizona reliever Brandon Lyon (2-4). Robert Fick sacrificed him to second and Lyon intentionally walked Soriano.

"Walk the leadoff guy. That's not the way you want to go," Diamondbacks manager Bob Melvin said. "You got to make them hit their way on base."

After Felipe Lopez walked to load the bases, Lyon lost Zimmerman on a full-count pitch. Zimmerman's bases-loaded walk gave him 90 RBI this season.

"I was looking for something to hit, trying to hit it to right-center and try to get the run in," Zimmerman said. "I was looking away. He was trying to nibble. I was surprised he came back with a 3-2 curveball."

Soriano tied the franchise record with his 44th homer in the ninth inning, a two-run shot to left that tied it at 6. His drive came off reliever Jorge Julio, who blew his first save opportunity since July 25.

"I didn't feel like I was gripping the ball," Julio said of his inside fastball to Soriano. "When I threw it, it slipped out of my fingers."

Chris Young went 3-for-5 with two doubles and five RBI for the Diamondbacks, who have lost nine of their last 11 games.

Young, playing in his ninth major league game, put starter Miguel Batista in position to win his fifth straight decision before Julio allowed Soriano's homer. Batista limited the Nationals to five singles and one run in seven innings. He struck out five and walked three.

"He threw the ball extremely well -- certainly good enough to win a game and should have won a game," Melvin said.

Chad Cordero (6-4) struck out two in two hitless innings to get the win.

Billy Traber started for Washington and allowed four runs and 10 hits in four-plus innings. The Nationals used four other relievers to get to Cordero.

Young gave Arizona a 4-1 lead with a two-run double in the fourth inning that scored Damion Easley and Stephen Drew.

Ryan Church pulled the Nationals to 6-4 with a three-run homer off Tony Pena in the eighth. Nick Johnson started the rally with a double and Austin Kearns followed with a walk.

Beltran Perez, acquired Friday from Double-A Harrisburg, made his major league debut in the sixth for the Nationals. He pitched two innings and allowed one hit.

Eric Byrnes and Johnny Estrada started the fifth with back-to-back singles that chased Traber. Chris Booker, acquired Friday from Triple-A New Orleans, made his Nationals debut in relief of Traber. Booker struck out Carlos Quentin and got Easley to hit into an inning-ending double play.

Quentin homered in the eighth for the Diamondbacks.

Notes

• Vladimir Guerrero hit 44 homers in 2000 to set the Montreal Expos/Washington Nationals franchise record for home runs in a single season. "I feel happy because it's a very good number personally," Soriano said of tying the mark.
• Booker, Perez and pinch-hitter Nook Logan are the 53rd, 54th and 55th players the Nationals have used this season, a National League high.
• This was the first time the teams have met since May 11, 2005.
• This was the first day-night doubleheader in Nationals' history.
• The Nationals are 7-5 in extra-inning games. The Diamondbacks are 6-5.
• Batista has not lost since June 20. He's won five straight decisions and had nine no-decisions, including his last four straight starts.