ST. PETERSBURG, Fla. — In tight games, such as the Boston Red Sox’ 2-1 loss to the Tampa Bay Devil Rays last night, there always seem to be a lot of little things that become magnified when you look back at them.

And that certainly was the case as Boston was denied a sweep of the three-game series at Tropicana Field, the first leg of a season-high 10-game trip that moves to Chicago for four games against the White Sox, beginning tonight.

The Red Sox had no one to blame but themselves for last night’s setback.

They didn’t hit with runners in scoring position, going 1-for-10 and leaving 14 runners on base. Even the one hit they managed to get with a man in scoring position didn’t help.

It turned into an out at the plate, with David Ortiz gunned down at home plate by Devil Rays center fielder B.J. Upton as Ortiz tried to score from second on Mike Lowell’s ground single up the middle in the fifth.

Starting pitcher Daisuke Matsuzaka, meanwhile, was a little erratic with his command (four walks, eight strikeouts in six innings), as has been an issue off and on all season. But the only mistake that hurt him was a high fastball that Upton slammed for a two-run homer to right after a walk to Carlos Pena in the sixth inning.

That blast was the 18th of the season off Matsuzaka, who gave up only two hits last night. His record fell to 13-10 and his solid earned-run average actually dipped from 3.79 to 3.76.

The loss left Boston with a 9-3 record against the lowly Rays this season. Dice-K has suffered all three of those losses in four decisions against Tampa, including a game here on July 29 that was scoreless until Matsuzaka was taken deep in the seventh by Dioner Navarro.

“This was frustrating because he threw the ball so well,” sighed catcher Jason Varitek.

There was plenty of frustration to go around, and Varitek suffered through his share.

The Sox’ captain went 0-for-5. While that looks bad enough, in each of his last four at-bats he came to the plate with runners at first and second and two outs.

Varitek has not been a good hitter with runners in scoring position and two outs this season. He was at .176 (9-for-51) in such situations when the game started. Now he’s down to .164 (9-for-55). He grounded weakly to first in the third inning, was overpowered for a whiff by Tampa Bay starter Edwin Jackson in the fifth, flailed at a pitch in the dirt against former Pilgrim High right-hander Dan Wheeler for a strikeout in the seventh, and ended the game by lofting a routine fly ball to left off closer Al Reyes.

“I got myself out,” said Varitek. “Jackson made some good pitches (including fastballs at 97 and 98 mph) but I chased a pitch away, I chased a pitch in and I chased a pitch up in those other three situations.”

Earlier, the Sox had had a chance to chase Jackson from the game. They filled the bases with none out in the third, but got only one run, on Mike Lowell’s sizzling sacrifice fly to left fielder Carl Crawford that delivered Dustin Pedroia from third base.

Two innings later, DeMarlo Hale waved home Ortiz as Lowell’s grounder rolled on the turf to Upton.

“At that part of the game, I figured Upton was playing deep and it was a routine ball up the middle. We had a chance to be aggressive there,” said Hale.

As Ortiz rounded third, he took a look back at Upton to see what was going on.

“I like to see where the ball is going to go (on the throw),” said Ortiz, adding he didn’t want to be faked out by the catcher as he neared home plate.

Hale said he didn’t think that glance slowed down Ortiz, nor did he think Ortiz should have just been running hard, trying to pick up a signal from the Sox’ on-deck hitter to tell him whether to stand up or slide, and which side of the plate to slide to.

“Sometimes it takes a while for the (on-deck hitter) to get there, so you go with your baserunning instincts,” said Hale. “But I thought it had to be a great throw to get him. It was. And no one talks about the job (catcher Josh) Paul did. The ball almost short-hopped him and he made the play. You tip your hat to him.”

Manager Terry Francona wasn’t about to second-guess Hale.

“I would never not send him there,” said Francona.

Matsuzaka , meanwhile, had to swallow another hard-luck loss.

“I don’t think I feel really stressed out about (losing tough) games, but I was frustrated about my pitching,” said Matsuzaka, who needed 111 pitches to get through his six innings.

“Tonight, I wasted a lot of pitches and I feel I got myself into trouble. The problem is I haven’t been able to go as deep into games as I would like,” he said.

He wasn’t about to second-guess himself about the pitch to Upton, either. It was a fastball, in a similar spot as other fastballs to Upton during the night.

“He fouled pitches and swung and missed pitches. I felt it was good location, but he hit it well,” said Matsuzaka, who had retired Upton on a grounder to third and a whiff in the two previous at-bats.

Varitek agreed it wasn’t a huge mistake.

“It was up a little bit — up more maybe than he wanted it — but it wasn’t a bad pitch,” said Varitek.

Just bad enough, it turned out, on a night when the Sox’ own wasted opportunities came back to haunt them.

skrasner@projo.com