Mary Keitany has retained her Virgin London Marathon title as Kenyan women enjoyed a 1-2-3 on the streets of the capital.
Keitany produced a storming finish to win in an unofficial time of two hours 18 minutes 36 seconds, a new personal best and more than a minute ahead of world champion Edna Kiplagat. World silver medallist Priscah Jeptoo was 24 seconds further behind in third.
In the men's race, Wilson Kipsang made it a Kenyan double with victory in an unofficial time of 2:04.44, just four seconds outside the course record set last year by Emmanuel Mutai.
Kipsang pulled away in the closing stages to win by more than two minutes, with compatriot Martin Lel finishing second after edging out Ethiopia's Tsegaye Kebede in a sprint finish.
Claire Hallissey was the first British athlete across the line in 11th place, but crucially clocked an unofficial time of 2hrs 27mins 44secs.
That was 40 seconds quicker than the time run by compatriot Jo Pavey in last year's race, putting Hallissey in pole position for the final Olympic place available alongside Paula Radcliffe and Mara Yamauchi.
Freya Murray also ran under Pavey's time, meaning the latter's gamble of not running in London looks to have backfired, with the team due to be confirmed.
Lee Merrien was the first British man across the line in 17th, but his time of 2:13.41 was outside the Olympic 'A' standard of 2:12.00.
Britain had plenty to celebrate in the wheelchair races, with David Weir and Shelly Woods making it a home double.
Weir claimed a sixth London victory, equalling the record of Tanni Grey-Thompson, by just one second from Switzerland's Marcel Hug, while Woods decimated the women's field to win her second title by almost four minutes ahead of Japan's Wakako Tsuchida.