Limo, the world champion in the 5,000 in 2001, broke away from fellow Kenyans William Chebor and Leonard Mucheru at the 22-mile mark and finished with a time of 2 hours, 9 minutes, 56 seconds for his first marathon victory in his sixth race.
"I didn't train as well for the L.A. Marathon as I did here," said the 29-year-old Limo, who stopped and waved to fans as he crossed the finish line as well as waving both hands in the air at the bands and cheerleaders on the course at mile 24.
"I was visualizing a perfect picture at the end," Limo said. "Over the last two miles as the bike rider was telling me my lead was 25 yards, then 50 yards, I just kept pushing and getting more confidence."
Yulia Gromova, 36, of Russia won the women's race for the third consecutive year, covering the new 26.2 mile course in 2:27:38.
"I love the weather here and the climate and the crowds, they are very encouraging here," Gramova said through an interpreter.
Chebor finished second in the men's race with a time of 2:10:13. Nicholas Arciniaga, 26, originally from Fountain Valley, Calif., and now living in Flagstaff, Ariz., was third in 2:11:47 for the highest finish of any American in this event since 1999 when Josh Cox was ninth.
"My plan was to sit on the leaders," said Arciniaga, a graduate of Cal State Fullerton. "I was able to do that for the first 10 miles, but the pack broke away from me. But I was running with Hendrick Ramaala (a former New York City Marathon winner from South Africa) and over the last 10K and I was able to catch a few more guys."
Arciniaga was eighth in last year's New York City Marathon.
Mucheru was fourth at 2:12:40 followed by Kenyans Simon Wangai (2:13:00) and William Biama (2:13:23). Ramaala was seventh at 2:14:41.
Gromova broke away from her nearest competitors at about mile 18. She said she wasn't too happy with the course, "because there were just too many turns. It was frustrating. Last year was better." This was her first marathon since winning in San Diego last year in a personal best of 2:27:37.
Ethiopians took the next three spots in the women's race with Shuru Diriba finishing at 2:29:09 followed by Serkalem Abrah (2:32:06) and Tiki Gelana (2:32:19.) Jemima Jelegat of Kenya was fifth at 2:32:31.
Sergio Gonzalez of Oceanside, Calif., won the men's half marathon in 1:07:17 while Jacquelyn Gallegos of Albuquerque, N.M., was first in the women's event in 1:21:00.