Michael Dwyer / AP Deena Kastor carries an American flag as she wins the U.S. women's Olympic marathon trials Sunday in Boston.

Michael Dwyer / AP Trials winner Deena Kastor, center, with Magdalena Lewy Boulet, left, and Blake Russell.

BOSTON — Deena Drossin Kastor is bound for Beijing.

The graduate of Agoura High School won the U.S. Olympic marathon trials Sunday, earning a berth in the Beijing Games by erasing a gap of almost two minutes to pass Magdalena Lewy Boulet in the last three miles. It will be the second Olympic marathon and third Olympics for Kastor, who ran the 10,000 meters in Sydney.

"I accomplished two major goals: first, to make the team and, secondly, to win," said Kastor, who won the bronze medal in Athens despite fading in the U.S. trials and finishing second. "It's an absolute honor that this is my third Olympic team. It feels just as sweet the third time around."

This time, she'll be joined on the American marathon team by two runners who just missed out four years ago.

Lewy Boulet took second and Blake Russell was third on Sunday.

Russell finished fourth in the 2004 trials, missing a spot on the Olympic team by 35 seconds, and Lewy Boulet was also on the outside, in fifth.

"After the disaster in 2004, we knew we had to develop a game plan to get where I am now," Russell said. "My goal was top three, by an inch or a mile. If I was third, that was as good as being first. I just didn't want to be fourth — again."

Kastor finished in 2 hours, 29 minutes, 35 seconds to earn a $50,000 prize and the chance for a $10,000 bonus if she lines up in Beijing. Lewy Boulet was 44 seconds back; Russell was 2:21 behind her, but an all-important 1:13 ahead of first alternate Zoila Gomez.

On a perfect morning for a marathon, with a clear sky and temperatures in the high 50s, 146 women set out on a loop course that crossed back and forth over the Charles River before leading them back onto Boylston Street for the traditional Boston finish. The roads and bridges were lined with thousands of fans, many of them runners planning to head to Hopkinton for today's 122th edition of the world's longest-running long run.

Wearing the favorite's bib No. 1, Kastor bobbed along in a blue singlet and white cap, taking off her sunglasses before making the final turn. She grabbed an American flag and waved it as she ran toward Copley Square, where no U.S. man has claimed victory in the Boston Marathon since Greg Meyer won in 1983.

Kastor, Lewy Boulet and Russell were all wrapped in American flags, handed U.S. Olympic team jackets and crowned with the olive wreath traditionally given to the Boston Marathon winner. They were invited to serve as honorary grand marshals for today's race.

Joan Benoit Samuelson, who at 50 said this would be her last competitive race, finished in 2:49:08 to set an American record for the 50-54 age group. The two-time Boston winner won the inaugural Olympic women's marathon in 1984 — the only U.S. medal in the event until Kastor took the bronze in Athens.

"It's been a great run," Samuelson said before turning to Kastor. "I'm handing the torch off to her now, and she can run with it. And I'm sure she will."

Samuelson crossed the finish line in a Red Sox cap, as she did when she won the Boston Marathon as a Bowdoin College senior in 1979.

"There have been some great years in between and some not-so-great years," said Samuelson, who has battled a series of injuries, "for the Red Sox and myself."

Kastor was an overwhelming favorite for the second consecutive trials, with a personal best that was 12 minutes faster than the next-closest competitor. But by Mile 14, Lewy Boulet led by 1:56 — the length of the 2,000-foot Harvard Bridge, the longest of the city's spans across the Charles.

Kastor made her move with about 10 miles to go, and Russell followed as the pack began to string itself out. Lewy Boulet's lead was 77 seconds as they passed the finish line to begin their final 6-mile loop, but it was down to 30 seconds at 22 miles and 8 seconds at the 23-mile mark.

As the runners ran on Memorial Drive in front of the stately columns of MIT, Kastor took the lead.

"I was already kind of succumbing to second place," Kastor said. "The gap started shortening a bit; that kind of fueled my fire. It was really the second half of the last lap that I thought I could win this race."

Kastor ran last year's Boston Marathon, finishing a disappointing fifth. Her training for Sunday's trials included running at other distances, which included a first-place finish at the U.S. 15K championship in Jacksonville, Fla.

Lewy Boulet, who has a 3-year-old son and works full time coaching at UC Berkeley, said she wasn't out to be the front-runner, but the slow pace set by the pack forced her to make a decision. Alone for the first 2 hours, she remembered what happened four years ago, when Russell led the first half of the trials but wilted in the St. Louis heat and finished fourth.

"There were a million things going through my mind, and Blake was one of them. I didn't want that to happen to me," Lewy Boulet said. "The plan was running the pace that I was running. The plan was not to run by myself."

A native of Poland, Lewy Boulet's citizenship swearing-in ceremony in San Francisco on Sept. 11, 2001, was cut short when the building was evacuated for fear that it would be attacked.

"I'm proud to wear this jacket," she said, puffing out the U.S. Olympic team jacket that she wore because she doesn't have a sponsor. "Coming from another country and having the opportunity to do whatever I wanted to do was a dream come true."

An hour highlight show of the race will air on MSNBC on Sunday.

Ryan Hall, Dathan Ritzenhein and Brian Sell earned spots on the men's team with their top-three finishes in the New York trials in November.