Radcliffe, a two-time world cross country champion, beat the previous mark -- set by Catherine Ndereba of Kenya in last year's race -- by 88 seconds. The British runner won her marathon debut six months ago in London.
"I'm really pleased," said the 28-year-old Radcliffe, who was fourth in the 10,000 meters at the Sydney Olympics. "It has rounded out a brilliant year for me."
Ndereba, who won the race the previous two years, was second, more than two minutes off the pace. She trailed Radcliffe from the start.
"I know she is very strong and has a good kick," said Ndereba, who was affected by the cold weather. "I knew she was going to fly."
Wearing a turquoise hat, white gloves and her blond hair in a ponytail, Radcliffe suffered through stomach cramps between the 22nd and 23rd miles but cruised to victory.
"The route was good, the course was fast," she said. "I even got a marriage proposal out there."