NEW YORK – Shane Spencer’s throw was bouncing to nowhere, along with the New York Yankees’ season. The dynasty was about to go down.

Then, Derek Jeter appeared as if beamed from a spaceship, grabbing the ball and making his now-famous backflip to the plate to nail Jeremy Giambi and preserve Mike Mussina’s shutout. Since then, it’s been a pinstriped parade through the playoffs, a push that put the Yankees in the World Series against Arizona starting Saturday night. The team that looked so old and feeble in losing the first two games to Oakland turned around and won seven of eight, becoming the first four-time pennant winner since the Yankees of 1960-64.

“Sitting on the bench, I saw the ball go over the cutoff man’s head,” Andy Pettitte said, “and I thought the run was going to score right there. And then Derek came out of nowhere.”

Like so many of these Yankees’ moments, they seem like movie scripts, too perfect for reality.

“That,” Pettitte said, “was the biggest lift for us.” The three-time defending World Series champions won three in a row against Oakland, ending the Athletics’ 17-game home winning streak, and advanced to the ALCS against Seattle.

Then they made the mighty Mariners, the team that had tied the major league record of 116 regular-season wins, look like the Devil Rays, taking two games in Safeco Field, winning Game 4 on Alfonso Soriano’s dramatic ninth-inning home run and then smoking Seattle 12-3 in Monday night’s finale.

Dead dynasty?

Ha!

“They have had so much success that they have got that confidence, and they seem to draw from it,” said Mariners manager Lou Piniella, a two-time World Series winner with the Yankees. “They feel that they can win these type of games. I know when I played here in New York, we felt, as a team, as individuals, that we would win big games.”

New York had beaten the regular season’s most dominant teams, who had combined to win 218 games. Seattle was the first club in 53 years to lead the AL in batting average, fielding and ERA.

Every day brought a different star. Paul O’Neill and Pettitte in the opener, Scott Brosius in Game 2, Bernie Williams and Soriano in Game 4, Williams, David Justice, Pettitte, O’Neill and Tino Martinez in Game 5.

No New York player had more than five RBIs in the series.

That’s the way the Yankees put together their run of four championships in five seasons, going 53-18 (.746) in postseason play. They’ve won 14 of 15 postseason series since Joe Torre took over as manager, including 11 in a row.

“You need 25 heroes,” Jeter said.

During the regular season, the Yankees were just sixth in the league in batting average and third in ERA. Every year they come together during their first 7 1/2 months together, forging bonds to pull for each other. And during the playoffs, they find a way to win – usually with the help of their opponent.

Since 1996, when the Yankees won their first World Series since 1978, New York has given up 13 unearned runs. The Yankees’ opponents have allowed 46.

An error by Oakland third baseman Eric Chavez allowed the go-ahead run to score in the final game of the division series and an error by Seattle third baseman David Bell led to four unearned runs that gave the Yankees a 4-0 lead Monday night.

“You can’t give a team like that extra outs,” Oakland pitcher Mark Mulder said.

After batting .288 during the regular season, the Mariners hit .211 against the Yankees. New York, with its huge scouting budget, found the way to shut down Seattle.

“They watched us all September,” Piniella said. “They had hoards of them following our team. They would come in waves.”

And the while the Yankees were beating Seattle, the eyes of the Yankees’ front office were on Arizona. Beating Curt Schilling and Randy Johnson will be a mighty task even for them.

While the Diamondbacks were understandably jubilant Sunday night after winning their first pennant, the Yankees were low key after their 38th, exchanging hugs in the clubhouse, where champagne was served in plastic cups – as if in a catering hall – instead of being sprayed. As reliever Mike Stanton said, winning pennants isn’t an end, its just step No. 3 of the four-step process of capturing another Series title.

Out on the field, Torre turned from the dugout and gave Mayor Rudolph Giuliani a hug, like so many others exchanged in Yankee Stadium since 1996. Then, arm in arm, they walked toward the mound, looking like Humphrey Bogart and Claude Rains in the final scene of “Casablanca.” Winning in the Bronx has produced many a “beautiful friendship.”