MLB

START BELIEVING

BOSTON – The Yankees won, and that just seems impossible if you had seen the first seven innings of last night’s game.

The Yankees were not bad. They were rancid. “It was ugly” is how Joe Torre phrased it. His Yankees embarrassed themselves in every phase of the game and, in particular, Jason Giambi set back first-base play to the Dark Ages because the only way to watch it without retching was in the dark.

So when Giambi homered to lead off the eighth inSning, it felt like the tiniest scratch at atonement. Except, as it turned out, that homer launched an improbable comeback from the horrible play that had ushered in a 7-2 deficit. In the eighth inning it was suddenly as if Bill Belichick were stealing signs and relaying to Yankees hitters what the Red Sox’s Hideki Okajima and Jonathan Papelbon were throwing before the pitch.

The Yankees did not stop hitting in the inning until they had scored six runs. They did not stop hitting until they had damaged Okajima, who had so tortured them early in the season, and also stomped on Papelbon. So that means they did not stop hitting until they had done another job on the Red Sox’s supposedly superior pitching and also on Boston’s psyche.

Again, if you watched the first seven innings of this game, you just would find it unfathomable to believe the Yankees actually won, 8-7.

“It was probably as bad as it gets and as good as it gets,” Alex Rodriguez said.

The bad was lowlighted by at least three horrendous plays on defense by Giambi. Derek Jeter was an embarrassment on both sides of the ball. Rodriguez continued his recent strikeout penchant. Heck, the whole lineup was brutal.

The Yanks put runners on in each of the first seven innings, but went 2-for-16 with men on base. Meanwhile, their poor defense was instrumental in forcing Andy Pettitte to throw a staggering 101 pitches in four innings.

As Torre followed Pettitte with a procession of Jose Veras, Sean Henn and Brian Bruney, it felt like surrender.

Again, I cannot emphasize this enough, it is staggering that the Yankees won this game.

“It wasn’t one of our better efforts,” Torre said.

Until the eighth.

Okajima had not given up a homer in 81 at-bats against lefty hitters, and then surrendered consecutive blasts to Giambi and Robinson Cano. Melky Cabrera walked and Johnny Damon, another lefty, doubled to left-center to leave runners at second and third. That knocked out Okajima and, interestingly, moved Boston manager Terry Francona to bring in Papelbon, his delicate closer, for a six-out save. The Red Sox led the division by 5½ games. It smelled like panic. But it should also have sewn up victory. Papelbon had not given up a run in 162/3 innings.

But Jeter singled, Abreu doubled and Rodriguez singled and four runs scored with Papelbon on the mound, two charged to him.

The stunning rally allowed the Yanks to climb within 4½ games of the Red Sox. But, more important, it permitted the Yanks to stay 3½ up on the surging Tigers. And, down the road, what might be most important, especially should the Yanks and Red Sox be ALCS dance partners again, is that the Yankees continue to bulldoze the best of the Red Sox pitching staff.

Okajima is no longer a mystery to their lefties. And the Yanks have now inflicted two of Papelbon’s three losses this season and one of his three blown saves. The Yanks also are 9-7 against the Red Sox this year. But they lost five of six to Boston in April when their pitching staff was in shambles. Since then, they have won eight of 10. But they never had a win in that period that looked like last night’s.

Because last night they won when for seven innings that seemed an impossibility.

joel.sherman@nypost.com