Record crowds estimated at being more than a million people lined the streets of the capital to watch the 29th Flora London today as Germany's Irina Mikitento (pictured) and Kenya's Sammy Wanjiru triumphed.
Wanjiru won in a course record of 2 hours, 5min 10sec, finishing ahead of the same two men who made the Olympic podium in Beijing.
This time, however, Beijing Games bronze medalist Tsegay Kebede of Ethiopia was second and Jaouad Gharib of Morocco was third.
Wanjiru had been on course to break Ethiopian Haile Gebrselassie's world record at the halfway point.
The 22-year-old Kenyan said: "The course was very hard, up and down.
"It was a bit of fast course."
Wanjiru used a series of surges to hold off Kebede, who finished the 26.2-mile race 10 seconds behind in a personal best.
Gharib was third in 2:05:27.
Defending champion Martin Lel pulled out of the race on Saturday because of a hip injury,
Mikitenko, 36, broke away from the field to win in 2:22:11.
In the final six miles, she surged ahead of Mara Yamauchi of Britain, who finished 61 seconds behind. Liliya Shobukhova was third in 2:24:24, one of four Russians in the top 10.
Mikitenko said: "I was always confident that I had it in my legs as everything in myself felt good, and after 19 miles I saw no reason why I shouldn't win."
The Japan-based Yamauchi ran a personal best of 2:23:12.
She said: "I've finally got under that 2:25 after making a big improvement with my training over the last year or so.
"I've been training at altitude and more towards marathons."
Olympic champion Constantina Dita of Romania slipped off the pace and pulled out after the halfway mark with breathing difficulties.
Beijing Games silver medalist Catherine Ndereba was seventh, and bronze medalist Zhou Chunxiu, the 2007 London champion, finished 12th.
Fun runners, charity fundraisers and those in fancy dress joined the top athletes in tackling the 26.2-mile course.
The runners left Greenwich Park on their way east past Woolwich Royal Artillery barracks before winding back to cross the river at Tower Bridge.
The course took them around Docklands to the City and across the finishing line on the Mall.
The weather was warm and bright, with temperatures of 12C (54F) rising to a maximum of 16C (61F) by around 2pm.