Oliver Perez #46 of the New York Mets pitches against...

Oliver Perez #46 of the New York Mets pitches against the Washington Nationals at Citi Field. (April 10, 2010) Credit: Getty Images

Oliver Perez shook his head at catcher Henry Blanco, confident that he knew better.

Unfortunately for the Mets, Perez didn't.

The lefty waved off Blanco's request for a slider and instead threw a fastball down the middle to Washington's Willy Taveras, who cracked a two-run triple to deep center to jump-start the Nationals' offense in the second inning Saturday at Citi Field.

"That pitch was supposed to be inside," Perez said, calling it a mistake on his part. "[Blanco] told me to throw a slider, but I changed the sign and threw a fastball in.''

But Perez didn't back down against Taveras in the fourth inning, either. And again, it cost the Mets.

After giving up an infield single to Ian Desmond in between walks to Adam Dunn and Ivan Rodriguez, Perez tried to throw a cutter to Taveras.

The outcome was the same: another hit for Taveras and two more runs for the Nationals.

"He gave me some pitches I could handle and I was aggressive and got some pretty good swings on it," said Taveras, who had a career-high four RBIs in his first start of the season in Washington's 4-3 win at Citi Field.

Perez, who threw 101 pitches (59 for strikes), allowed four runs, four hits and four walks in 52/3 innings, striking out six.

Mets manager Jerry Manuel defended his pitcher, who also went 1-for-2 with an RBI single, his first run batted in since June 13, 2008.

"Taveras put some good at-bats on him in key situations," Manuel said of the outfielder, signed to a minor-league contract in February after being let go by Oakland. "I don't think it was a matter of what Ollie was doing as much as we ran into a guy who was hot."

Perez didn't appear to be upset by the loss.

"I think I did everything [I could], so I have to be happy about that because sometimes you're going to win and sometimes you're going to lose," he said. "We lost today. It's OK. We have to try to win tomorrow. Everybody played 100 percent. One team had to win today and they played better than us today."

But as the throng of reporters left his locker, there was a slight edge in his voice, a tone of frustration that hadn't been evident a few moments earlier.

"I think he made really good contact and that's why he got four RBIs. Sometimes, I think, you have to tip your hat. He had a really good day," he said.

"I would try to change the way I threw at him," he added. "It upsets me, because we lost. You can't be happy about that."