BOSTON — Robert Cheruiyot won his fourth Boston Marathon today, and Dire Tune outkicked Honolulu Marathon champion Alevtina Biktimirova by 2 seconds in the closest finish in the history of the women's race.

Cheruiyot ran away from the pack to finish in a blistering 2 hours, 7 minutes, 46 seconds. He missed the course record he set two years ago by 32 seconds, but became the fourth man to win the world's oldest annual marathon four times.

Cheruiyot and Tune, who finished in 2:25:25, each earned an enhanced prize of $150,000 — the biggest in major marathon history.

Abderrahine Bouramdane was 1:18 behind Cheruiyot and Khalid El Boumlili came in third, another 1:31 back. Nicholas Arciniaga, of Fountain Valley, Calif., was 10th to give the Americans a top-10 finish for the fourth straight year.

With his third straight victory, Cheruiyot gave Kenya its 15th men's victory in 17 years. Tune was the first Ethiopian woman to win since Fatuma Roba won three straight from 1997-99.

Cheruiyot pulled away from a pack of four at the base of the Newton Hills, running the 19th mile in 4:37 to finish Heartbreak Hill 27 seconds ahead of his Moroccan pursuer. He passed defending women's champion Lidiya Grigoryeva, with the two No. 1 bibs running side-by-side, just before the 24-mile mark.

Cheruiyot remained on a record pace as he approached Kenmore Square before slowing over the last mile.

Tune and Biktimirova came into Kenmore Square side-by-side, jockeying for position. Biktimirova appeared to get an edge when Tune nearly missed one of the final turns and ran into a camera vehicle. The Ethiopian quickly composed herself and took the lead before the last turn.

Biktimirova caught her and regained the lead briefly, but Tune pulled ahead for the good in the last 100 yards on Boylston Street to beat her to the line.

Biktimirova won the Honolulu Marathon in 2:33:07 on Dec. 9. She was second here in 2006.

The previous closest women's finish came two years ago, when Rita Jeptoo beat Jelena Prokopcuka by 10 seconds. Jeptoo finished third this year, 69 second behind Tune.

The race came a day after the U.S. Olympic women's trials featured the top American runners fighting for a berth in the Beijing Games. Deena Kastor, Magdalena Lewy Boulet and Blake Russell finished in the top three to earn a chance to run in the Olympics.

With the three new Olympians serving as grand marshals, more than 25,000 runners left Hopkinton under cloudy but calm skies and temperatures in the 50s — a major improvement over last year's monsoon that threatened to scuttle the race.

Among those in the event's second-largest field: seven-time Tour de France winner Lance Armstrong, who finished 488th in 2:50:58.

Before the race, Spyros Zagaris, mayor of Marathon, Greece, presented Hopkinton with a replica of a cup that was given to the winner of the first modern Olympic marathon in Athens in 1896. He vowed to build strong ties between his city and Hopkinton, both homes of the start of famous marathons.