WASHINGTON -- Entering Wednesday's action, right-hander Shairon Martis looked good in his first two big league starts, but the third time wasn't the charm as the Mets outslugged the Nationals, 9-7, at Nationals Park.

Martis had a feeling it would be a tough night based on what he went through during his bullpen session a few hours earlier. Martis had trouble commanding his fastball in the session, and he paid for it during the game.

Martis lasted three innings and gave up six runs on five hits. He struggled starting in the first inning, when he gave up solo home runs to Jose Reyes and Carlos Delgado.

The second inning was Martis' only clean inning, but, in the next frame, the Mets scored four runs off him. Carlos Beltran highlighted the scoring with a two-run homer to make it a 6-1 game.

"I was a little too wild," Martis said. "I missed some spots. The ball was moving a lot. It's tough, especially with that team."

After Martis left the game for pinch-hitter Ryan Langerhans, manager Manny Acta told the young right-hander, "Be ready for the next start and be focused."

"I'm going to keep my head up, keep pitching and see what happens after that," Martis said. "I have to locate my fastball and throw it in the strike zone. I kept missing my spot, and they kept hitting it."

The Nationals couldn't figure out Mets right-hander Brandon Knight, who lasted five innings and gave up two runs on six hits.

"Earlier in the game, he was elevating his fastball and he had that overhand breaking ball -- it's a tough combination for right-handed hitters," Acta said. "Once the game went on, guys were laying off the high fastball. They got a couple of walks and a couple of hanging breaking balls. We were able to chase him out of there, but he was pretty effective earlier in the game.

It looked like Washington had a chance to get to Knight and tie the score at 2 in the second inning. Down 2-0, Washington was able to cut the lead by one when Kory Casto doubled to right-center field to bring Elijah Dukes home. But Casto broke the momentum when he was doubled off second base after Emilio Bonifacio lined out to Beltran in center field.

"I thought it was going to get into the gap," Casto said. "I read it and I figured if Beltran was going to come up with it, he had to break right away. He ended up catching it. I saw the ball was staying true and it wasn't going to fall. I tried to get back.

"It was a bad read. I was trying to score. It would have tied the game up at 2 if that would have dropped. I was trying to be aggressive, but I made a mistake. I got a little too far from second.

Pinch-hitter Alberto Gonzalez also killed a chance to extend a rally in the bottom of the sixth inning. After he singled off Ricardo Rincon to drive to drive in Bonifacio, Gonzalez went to second on a wild pitch. But Gonzalez tried to go to third base just as Willie Harris went to first on a walk. Gonzalez actually thought the ball went past catcher Brian Schneider.

"Gonzalez was not trying to trying to trick anybody -- he just didn't see the ball," Acta said.

The baserunning blunders weren't the only thing that hurt the Nationals. Acta put in four relievers and only Garret Mock would prevent the Mets from scoring.

In the fourth inning, Jason Bergmann gave up a run-scoring single to Jose Reyes, while Levale Speigner allowed Argenis Reyes to score on a double-play ball hit by Marlon Anderson two innings later.

In the eighth, Beltran ended up homering from the right side of the plate off Charlie Manning.

"The bullpen couldn't stop them. They scored on every guy except for Mock," Acta said. "So the Mets kept coming and scoring runs."

In the seventh inning, the Nationals made it close off right-hander Brian Stokes, as Dukes hit a two-run homer to make it an 8-5 game.

Wil Nieves drove in a pair of runs with two outs in the ninth to make it a 9-7 game. Roger Bernadina was the next hitter and he was the tying run at the plate, but Luis Ayala ended up striking out Bernadina to end the game.

"Ayala threw real hard," Bernadina said. "This time he got me. I'll just try to be tougher next time."