Farah just missed out on his personal best by four seconds as he finished in 59 minutes and 26 seconds, half a minute ahead of New Zealand's Jake Robertson in second place.
Favourite Vivian Cheruiyot finished strongly to win her second women's title in one hour, seven minutes and 43 seconds, while David Weir won the men's wheelchair race for the seventh time
Victory this weekend makes Farah the first man to win the world famous half marathon five times, and is the ideal preparation for his appearance next month at the Chicago Marathon.
Farah said: "I'm still learning and understanding more and I'm not afraid to mix it in. In 2014, I was afraid to mix it because it was their territory and I was a track runner. But now I'm not afraid of anything.