Kirui won with an unofficial time of 2 hours 11 minutes and 47 seconds, and Sule Utura's time was 2 hours 33 minutes and 50 seconds.
An estimated 24,000 people are participating in the event.
The course starts at Dodger Stadium and goes through Silver Lake, Echo Park, West Hollywood and Beverly Hills and ends in Santa Monica. Affected roads are being re-opened on a rolling basis.
People from all 50 states and more than 63 countries are taking part in the 26.2-mile route.
Get a look at the route below.
City News Service contributed to this report.