BOSTON — The key at-bat last night came in the seventh inning with the bases loaded, the Sox trailing, 6-2, and Big Papi, David Ortiz, at the plate with two outs.

The stage was set for Ortiz heroics.

Cleveland manager Eric Wedge brought in left-hander Aaron Fultz for the classic one-batter, lefty-lefty confrontation.

And it was quite a battle, a nine-pitch test of physical and mental wills.

Fultz got the jump in the at-bat, with Ortiz swinging hard and not coming close to the first pitch, a breaking ball on the outside corner. The next pitch, another breaking pitch, was just outside. Fultz threw yet another breaking ball and Ortiz barely got the end of his bat on it for a foul ball, moving the count to 1 and 2.

Fultz then tried to surprise Ortiz with a fastball in, a dangerous pitch that Ortiz could have turned on. But he fouled it back. The next two pitches were breaking balls on the outside corner, and again Ortiz barely fouled each of them, the ball grazing the end of his bat.

On the seventh pitch, Fultz again tried to hit the outside corner with a breaking ball, but Ortiz laid off the close pitch and took it for a ball, making the count 2 and 2.

Fultz and catcher Kelly Shoppach decided the eighth pitch might be a good one to try again to fool Ortiz, who was by now looking out over the plate. Ortiz was not fooled. He crushed the slider — but he got around on it a tad too quickly, sending it to the foul side of the Pesky Pole.

With the crowd of 37,091 roaring louder with each pitch, Fultz threw yet another breaking ball. It wasn’t his best one of the at-bat, a little more over the plate than he might have wanted, but it was effective.

Ortiz his a soft liner to third baseman Casey Blake, who was swung over in the Indians’ shift, close to where the shortstop generally plays.

No heroics. The score remained, 6-2. And Cleveland quickly added a pair of runs in the eighth for an 8-2 edge.

“That was the most intense pitch-against situation of the game, hands down,” said Shoppach. “We talked about it. We were going to be aggressive and make our pitch. We just didn’t want to leave anything over the middle of the plate. Aaron did a great job.”

Well, except for the slider that Ortiz cranked foul to right.

“Uh, that was a slider down the middle. We got lucky,” said Shoppach.

“That was a bad slider,” said Fultz. “But it was a bad enough pitch to where it would have been tough for him to keep it fair. He hit it as good as he can hit a ball. I was trying to keep my pitches away from him and keep the ball down. I was aggressive with my slider and made some good pitches.”

Ortiz figuratively tipped his cap to Fultz — for this matchup, anyway.

“He made some good pitches,” said Ortiz. “He was trying to stay away from me and he did. I was fighting, but he won the fight. But I’ll get him next time.”

Too many fat pitches

One of the things that makes Daisuke Matsuzaka so difficult to hit, if he has any semblance of command, is the fact he has an unusual number of pitches he regularly uses.

That also makes it a bit difficult for catcher Jason Varitek, who has to figure out which ones are working the best.

Last night the testing-out process began, as usual, in the first inning. Dice-K threw five different pitches in his first 10 deliveries to the plate. His first four pitches of the game, in order, were fastball, changeup, slider, cutter. He threw a splitter on his 10th pitch.

Unfortunately for Dice-K and the Sox, the Indians were on every type of pitch he was throwing in the sixth, when he gave up four runs and plunged the Red Sox into a 6-2 hole.

Trot Nixon and David Dellucci (RBI) each drilled a double on a fastball. Josh Barfield yanked a down-and-away changeup for a run-scoring to left and Grady Sizemore crushed a slider for a two-run homer into the Indians’ bullpen.

The moral of the story for Matsuzaka last night was that no matter how many types of pitches you have, if they’re fat in the strike zone, they’re going to get mashed at the big-league level.

“We hadn’t seen him before and he was throwing everything from the outset,” said Cleveland manager Eric Wedge. “We got to see that. Once we did, we made some adjustments.”

Technique atrocious

The call — a fair ball — was correct by first-base umpire Tim Timmons.

But his technique was awful, leading to an argument from Boston manager Terry Francona.

Nixon smoked a ball inside the first-base line, leading off the sixth. Timmons had to spin out of the way of the ball and pointed toward foul territory. His spin-a-rama, though, had pointed him in the wrong direction. He had meant to point to fair territory because the ball clearly had been a fair ball.

By then, prompted no doubt by the foul call, the ball girl went after the ball and had it deflect off her and into fair territory. That made it a dead ball and Nixon was awarded a ground-rule double.

Francona argued. Had it not been called foul and the ball girl touched it, the ball might have kicked off the wall and Nixon would have had a single, not a double. But the ground-rule double call stood.

skrasner@projo.com