The Celtics, who have 16 championships but have gone without one for more than two decades, obtained the former MVP and 10-time All-Star today in a 7-for-1 deal — the NBA's biggest trade for one player.

Boston sent the Minnesota Timberwolves forwards Al Jefferson, Ryan Gomes and Gerald Green, guard Sebastian Telfair and center Theo Ratliff, two first-round draft picks and cash considerations. Besides Ratliff, 34, the other four are 22 or younger.

With Paul Pierce and Ray Allen already on the roster, the Celtics have been transformed from a promising collection of youngsters who had the NBA's second-worst record last season into an instant contender in the mediocre Eastern Conference.

"This is probably my best opportunity at winning a ring," Garnett said. "It was a no-brainer."

The Celtics won their last championship, the third with the original Big Three of Larry Bird, Kevin McHale and Robert Parish, in 1986. Two members of that club orchestrated today's blockbuster trade — Celtics executive director of basketball operations Danny Ainge and Timberwolves vice president of basketball operations Kevin McHale.

But Ainge cautioned that it's much too early to equate the two trios.

"These guys will never be the Big Three until they win" a championship, he said.

The Timberwolves get the Celtics' first-round pick in 2009, unless it is among the top three, and a return of Minnesota's conditional first-round draft pick obtained in January 2006 when they sent Ricky Davis to the Timberwolves for Wally Szczerbiak.

The previous biggest NBA trade for one player came in 1999, when Houston obtained Scottie Pippen from Portland for six players.

The Garnett trade eclipses the latest one involving an NBA star, Allen Iverson. Philadelphia traded the guard and Ivan McFarlin to Denver last Dec. 19 for Andre Miller, Joe Smith and two first-round draft choices.

"This is a tremendous day," said a smiling Pierce, who had been frustrated for years as the sole star on a rebuilding team. "I feel like a rookie again."

The key to the deal for Minnesota is Jefferson, whom the Celtics were reluctant to part with. He had a breakout season in 2006-07, his third with Boston, when he averaged 16 points and 11 rebounds after struggling with injuries. He joins a youth movement in Minnesota, which drafted forward Corey Brewer from Florida.

"The past few seasons our on-court performance has been disappointing to our fans, myself, (owner) Glen Taylor and the entire organization," McHale said. "Through this trade, we have obtained very talented, young players with a lot of potential, future flexibility with the salary cap and two future first-round NBA draft picks.

"Personally, I want to thank Kevin for all of his hard work through the years and what he has meant to the Timberwolves franchise."

The teams had discussed a trade for the 6-foot-11 Garnett, the NBA's leading rebounder each of the past four seasons, before the June draft. But he preferred other teams than Boston, and the Celtics didn't want to give up Jefferson.

The acquisition of Allen, 32, in a draft-day trade with Seattle to go with Pierce, 29, was a major factor in changing Garnett's mind. It gave Garnett, 31, a better chance at a title after Minnesota missed the last three playoffs in the tough Western Conference.

He also realized that he didn't fit in with Minnesota's strategy of rebuilding with youth and was amazed at all the activity to finalize the trade.

"It's like being in a Lamborghini doing 200 (mph) with your head stuck out the window," Garnett said. "It's been like a whirlwind the last 72 hours."

The Celtics' other starters are second-year point guard Rajon Rondo and center Kendrick Perkins. Only nine players are under contract, although they are expected to sign second-round draft picks Glen Davis, a forward from LSU, and Gabe Pruitt, a guard from Southern California.

The Timberwolves came within two wins of the NBA finals in 2004. Garnett averaged 24.2 points and a league-high 13.9 rebounds that season, joining Bird as the only players to average at least 20 points, 10 rebounds and five assists for five consecutive years.

But Minnesota has fired two coaches and not made the playoffs since. Garnett never said he was unhappy and never asked to be traded, but expressed frustration with some of McHale's personnel decisions and challenged him to upgrade the roster.

Garnett was the fifth player drafted in 1995, coming out of Farragut Academy in Illinois and skipping college. He has averaged more than 20 points and 10 rebounds for each of the last nine seasons. He is among five players in NBA history with at least 19,000 points, 10,000 rebounds and 4,000 assists. The others are Wilt Chamberlain, Kareem Abdul-Jabbar, Karl Malone and Charles Barkley. He also is an outstanding defensive player and an excellent passer.

The Timberwolves had lost 60 games in each of the four seasons before Garnett arrived. But in his second season, he helped lead them to the first of eight straight playoff appearances.

Before his third season, Garnett got a six-year, $126 million extension in 1997.

With Garnett, seven-time All-Star Allen and five-time All-Star Pierce, the Celtics upgraded their profile in a sports market dominated by the New England Patriots and Boston Red Sox. Owners John Henry of the Red Sox and Robert Kraft of the Patriots and Boston Bruins executive vice president Charlie Jacobs all called to congratulate Celtics co-owner Wyc Grousbeck.

In his four full seasons as executive director of basketball operations, Ainge has stockpiled youngsters. He could be patient and let them develop or speed the process through trades for stars.