Florence Kiplagat dropped to the ground while giving the crowd a thumbs up after crossing the finish line at the Chicago Marathon Sunday.  

Kiplagat, of Kenya, won the women's race, finishing with an unofficial time of 2:23:33.

"The course for me was very nice," she said. "It was a flat course, sometimes it's windy, but that is part of competition."

Kiplagat, the top woman in the Chicago Marathon elite field this year, holds the world record for the half marathon and returned to compete in Chicago after a third place finish in 2014. Kiplagat was awarded second place that year after Rita Jeptoo was stripped of her marathon title because of doping.

Her personal best marathon time, 2:19:44, dates from the 2011 Berlin Marathon.

American Deena Kastor, who won the Chicago Marathon 10 years ago, earned an American women's master's record with an unofficial time of 2:27:47.