Bernard Lagat ran 1:02:33 in his first-ever half, finishing in 12th place.
Wilson Kipsang won it in 1:01:02 in freezing temps and light snow.
Daniel Meucci was 2nd 4 secs back, with Ritzenhein 3rd another 4 secs back of Meucci.
Jason Hartmann was 9th in 1:01:52, with Abdirahman 15th in 1:03:20.
Caroline Rotich won the women's race in 1:09:09.
Second was Diane Nukuri-Johnson in 1:09:12.
Lisa Stublic was 3rd in 1:09:18.
Top American was Stephanie Rothstein Bruce in 1:10:53.
Lagat stayed with the front pack through 15K in 43:56, then fell back.
