Ethiopia's Askale Merachi won the women's race and set a race record.
Barno crossed the finish line in 2 hours, 11 minutes, 46 seconds and beat Korir by seven seconds. It is the second time in three years that Barno has won at Los Angeles. He finished third last year.
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Mexico's Juan Luis Barrios was third in 2:11:59. Tyler McCandless was the top American finisher in 11th in 2:14:57.
Merachi finished in 2:24:12 to beat Kenya's Cynthia Jerop by 1:43. She beat the race record, set by Lidiya Grigoryeva in 2006 (2:25:10) by nearly a minute.
Merachi and Jerop broke away from the pack at the midway point before Merachi took control over the last six miles.
Kenya's Lucy Karimi was third (2:26:16). Lindsey Anderson was the top American in sixth at 2:34:45.