ST. PETERSBURG -- Sometimes, it takes nothing more than a couple of poorly executed pitches for an entire night to go up in flames. That is exactly what happened to Justin Masterson and the Red Sox in Friday night's 6-2 loss to the Rays, as a couple of sinkers didn't sink, and Tampa Bay's two most powerful hitters made the mistakes painful.

How does as a 2-1 lead become a 6-2 deficit in a swift three-pitch sequence?

It happens when Evan Longoria pummels a grand slam to left field, and Carlos Pena follows with a mammoth solo shot to right on an 0-1 pitch.

"Pretty much, the inning got out of hand," said Masterson. "I made a poor pitch decision to Longoria, one that got out and over the plate, and he put it where he was supposed to. It was unfortunate the way that happened. Unfortunately, aside from that, I felt really good about the outing."

Longoria has wrecked the Red Sox in the first two games of this series. His three-run double against Josh Beckett was the catalyst in what turned out to be a complete unraveling of a 13-0 loss. And this time, he again jumped on a mistake in the upper portion of the strike zone.

"He gets in a situation where you leave a pitch up to one of the best hitters in the game, and he does exactly what you don't want him to do," said Red Sox manager Terry Francona. "We elevated a ball, and it's a four-run swing. With two outs, it's a big swing in the game."

Masterson doesn't think that the grand slam made him lose concentration on Pena.

"It was a sinker that was up, up, up," Masterson said. "Pitches were getting up that inning, which was not what we wanted to have. It's never good leaving pitches up. He's probably amped up trying to go back-to-back, and he did. It was just another kind of poor pitch."

Masterson wasn't the only one who wished he could have a take-back on the pitch to Longoria.

"We were one pitch away. I'll take the blame on that one on the Longoria at-bat," said Red Sox catcher Jason Varitek. "We made some bad pitch selections, and he made us pay."

It wasn't merely a frustrating night on the mound for the Red Sox.

Offensively, Boston let one early opportunity after another go by against Tampa Bay starter Andy Sonnanstine. On a night the Red Sox had nine hits, they left 10 men on base.

In the first, the Sox had first and second and one out, when Dustin Pedroia thought he could advance to third on a wild pitch. Instead, the ball, after bouncing, came right back in the vicinity of Rays catcher Dioner Navarro, who rifled a strike to third to nail Pedroia by about 10 feet.

"The ball bounced right to Navarro in the first inning, he got Pedey going to third being aggressive, which is OK," said Francona.

Then, an inning later, with two on and two outs, Julio Lugo just missed a three-run homer. His drive to left fell just short of the wall.

"I thought it had a chance, but I hit the ball off the end of the bat," said Lugo.

Although Tampa Bay has struggled out of the gate, going 10-14, the Rays are 4-1 against Boston. After reeling off 11 wins in a row, the Red Sox have lost three of their last four.

"It's part of the game," Lugo said. "We're playing well. We've lost two games -- it's not the end of the world right now."

If there is one element that has contributed most to the mini-skid, it has been the starting rotation.

Masterson was the fourth straight Boston pitcher to give up five earned runs or more.

"Again, I just think it comes down to attacking the strike zone a little bit better," Francona said. "Stuff is plenty good all the way around. When we attack and we work ahead, you'll see guys get deeper, and you'll see more success."

The Red Sox jumped out first when Sonnanstine walked Jason Bay with the bases loaded and two outs in the third.

Masterson shut down the Rays early, buying the Red Sox time to extend their slight lead. They did just that in the fifth, with J.D. Drew hammering a single to right that scored Kevin Youkilis from second.

However, the night was ready to go downhill fast for the Red Sox and for Masterson, who allowed six hits and six runs over six innings.

"I was disappointed after five other innings that we did so well," Masterson said. "Then that one inning just kind of ballooned."