The San Antonio Spurs woke up last Tuesday to a new identity: They were no longer the best team in the N.B.A., the Western Conference or their division.

They are not even the best in Texas.

The Dallas Mavericks outlasted the Spurs in an exciting second-round series, winning Game 7 in overtime last Monday night and tipping the balance of power in what can now be called a great rivalry.

"It was so close — two overtimes, three games by one or two points, it was very good basketball," San Antonio point guard Tony Parker said. "It just didn't go our way."

The Spurs trailed by 3-1 in the series and were behind by 20 points in Game 7, despite playing at home. They rallied to take their first lead in the closing minutes but could not hold it.

"We had a last chance to make the shot and win the game and the series," said Manu Ginóbili, who fouled Dirk Nowitzki on a layup with 21 seconds left in regulation, leading to the tying point, then missed a potential winning shot with about 6 seconds left.

"It is hard," he said. "You have to move on and go on from it."

The Spurs have long been the bullies along Interstate 35, collecting division titles and championships while the Mavericks kept changing players and identities. San Antonio respected Dallas but never doubted it was the better team.

The series changed that. And with the former San Antonio star Avery Johnson having used his version of their system against them, the Spurs face the legitimate concern that the Mavericks are the team with the brighter future.

Dallas proved to be younger, faster, deeper and more balanced than the Spurs. Sure, it took an entire series and then some to prove it — and then only barely — but those tiny differences tend to get wider over time.

So it is only logical to expect whatever moves Spurs Coach Gregg Popovich and General Manager R. C. Buford make in the coming months will be done to help them match up with the Mavericks.

The Spurs certainly will not overhaul anything. This team set a franchise record for victories in the regular season, and is coming off two titles in three years and three in seven.

Even if they wanted to, it would not be easy. San Antonio already has 10 players under contract for next season.

The most significant free agent is center Nazr Mohammed, who hardly played against Dallas as Popovich went mostly with the 6-foot-11 Tim Duncan and four players 6-7 or shorter. The reserve guard Nick Van Exel has talked about retiring.

Free agents may consider taking less money to play with Duncan, Parker and Ginóbili, and to be part of a winning organization. That is what lured Michael Finley, a former Maverick who started two playoff games.

Other than trades, San Antonio may look overseas. The Spurs own the rights to Ginóbili's fellow Argentine Luis Scola, a 26-year-old power forward; Parker's fellow Frenchman Ian Mahinmi, a 19-year-old power forward; and Lithuania's Robertas Javtokas, a 26-year-old center.

The ages of those players might be especially intriguing.

The 24-year-old Parker and Ginóbili, 28, were the only 20-somethings San Antonio used in Game 7.

While Duncan turned 30 during the first round and proved he was still in the prime of his career (41 points in Game 7, career-best 32.3 a game against Dallas) and defensive whiz Bruce Bowen shows no signs of turning 35 next month, time is ticking for the rest of the Spurs.

Finley, a reserve most of the season, is 33. The three players who came off the bench were the 34-year-olds Van Exel and Brent Barry, and the 35-year-old Robert Horry.

Considering the reserves scored two points Monday night, adding players with younger, fresher legs who can provide Popovich with more scoring options and more lineup combinations might be high on the off-season to-do list.

The Mavericks, and the rest of the N.B.A., certainly are bracing for San Antonio to remain tough.

The organization blended Duncan with David Robinson to win a championship, won another with Robinson as a spare part, then won again without him.

And they did go down fighting this year.

"This is the best series I've ever played," Duncan said. "It was about the ball, whether the ball bounced one way or another, and the result is just how it bounced."