SAN ANTONIO ? First came a blocked shot, one of eight for Tim Duncan. Next came his two-handed, overhead pass to Stephen Jackson at the three-point line — swish!

Finally, Duncan found Jackson again for another three-pointer to complete his triple-double, and so much more.

The San Antonio Spurs won the NBA championship Sunday night behind a devastating all-around effort by Duncan, using a run of 19 unanswered points in the fourth quarter to defeat the New Jersey Nets, 88-77, and take the series 4-2.

“I thought this was the most poise we’ve shown all season long,” Duncan said. “We were all confident we would turn the game to our favor.”

Duncan finished with 21 points, 20 rebounds and 10 assists for a triple-double. San Antonio won the title for the second time in franchise history, sending David Robinson into retirement with the ultimate present.

“How could you walk away any better than this,” Robinson said. “This is awesome.”

He jumped and did a 360 as he punched his fist in the air and then hugged several teammates after being replaced with 35.6 seconds left.

The fourth quarter was stunning for its turn of events, with the Spurs — after trailing for almost the entire game — using the 19-0 run to take the life out of the stunned Nets.

It was the fifth straight NBA title for a Western Conference team. The Nets showed none of the characteristics of a championship team as the game got away from them quickly.

Coach Byron Scott left several reserves in during San Antonio’s big run, letting them play alongside Kenyon Martin as he struggled through one of the worst games of his career, shooting 3-for-23.

San Antonio outscored New Jersey 25-11 in the fourth quarter, with Duncan getting six rebounds, three assists and three blocks. San Antonio tied the finals record with 13 blocks in the game, and Duncan’s 32 in the series broke Patrick Ewing’s championship record.

Robinson completed his 14th season with a strong performance, grabbing 17 rebounds, scoring 13 points and blocking two shots.

As the buzzer sounded, he ran across the court looking for somebody to hug, and he found his son wearing a Robinson jersey and black-and-silver wig. He picked him up, then hugged his mother as silver, black and white confetti fell from the rafters.

“I was just trying to give us whatever energy I could. We finally hit some shots in the fourth quarter,” Robinson said.

Duncan hugged and kissed his wife, Amy, while 19-year veteran Kevin Willis cried and gave a long hug to veteran Steve Smith — both of them having finally won a title.

Jackson finished with 17 points, nine of them on 3-pointers in the fourth. Speedy Claxton scored 13 and Manu Ginobili added 11.

“The guys were incredible,” Duncan said. “We played the whole way through.”

Jason Kidd led the Nets with 21 points, and Kerry Kittles had 16 in his best game of the series. Kittles, however, was on the bench watching alongside fellow starter Richard Jefferson as the Nets collapsed early in the fourth with the struggling Lucious Harris and Rodney Rogers on the court together.

“We gave everything we had,” Kidd said. “We weren’t up to it. You don’t want to lose. Hopefully we can get back and win another one. The basket got big for them, and they made it.

The first sign that the Nets were breaking down came when Duncan found Malik Rose all alone under the basket for a layup that cut New Jersey’s lead to 72-65. Rogers and Dikembe Mutombo grimaced at each other as the Spurs turned upcourt.

A three-pointer by Jackson made it a two-point game, and another three by Jackson gave the Spurs the lead for good with 6:34 left.

Robinson put back a miss by Duncan, Claxton hit a jumper from behind a screen, Jackson hit yet another three off Duncan’s 10th assist and Claxton scored again from outside.

San Antonio led 82-72, stirring the fans into a frenzy at the SBC Center and leaving the Nets hanging their heads with the outcome all but certain.

San Antonio became only the ninth franchise with two or more championships. The Spurs won their first in 1999 against the New York Knicks.

New Jersey lost in the final for the second year in a row, getting swept by the Los Angeles Lakers last season.

They both hurt.

“It’s never happy to lose,” said Kidd, who will be a free agent this summer and could leave New Jersey — possibly to sign with the Spurs.

“I’ve got a lot to think about. The door’s open, and I’ve got to play my free agency out. I would love to be a Net, but I’ve got to look at all my options.”

Duncan appeared to possibly be on his way to a quadruple-double at halftime, with 14 points, eight rebounds, six assists and five blocks. The usually low-key league and finals MVP even got charged up, pumping his fist and yelling after making a 2-footer with three Nets draped on his arms.

Duncan made the ensuing free throw to complete the three-point play, and his 7-footer with 40 seconds left gave San Antonio its first tie since the opening tip, 38-38.

Kidd answered 21 seconds later with a three-pointer to give the Nets the halftime lead, and things quickly went bad for the Spurs after intermission. Jackson committed his fifth turnover just 10 seconds into the quarter, leading to a fast-break layup by Kittles.

Eleven of New Jersey’s first 17 points came on the fast break, with Jefferson completing a 14-5 run to open the quarter. He took a lookaway pass from Kidd and was fouled on a tough layup, converting the three-point play for a 55-43 lead.

Following a timeout, Parker threw the ball away on the Spurs’ first possession, then hit a jumper, then traveled.

The turnovers wouldn’t stop, but the Spurs stayed within striking distance. Robinson led the way by doing the little things — drawing two charges and slamming home a missed shot.

The Spurs pulled to 59-55 on an 18-footer by Claxton, but that was the end of their run. Mutombo checked in and immediately grabbed an offensive rebound, leading to a corner jumper by Kittles.

Mutombo swished two foul shots with 35 seconds left in the quarter to help New Jersey take a 63-57 lead into the fourth.

Kidd hit the first two shots of the quarters — both mid-range bank shots — to quickly put the Nets back up by 10. It was 72-63 after a 3-pointer from the corner by Rogers, but San Antonio then made its big run.