Yamauchi ran the second fastest British marathon time last year in London
British woman Mara Yamauchi won the New York Half Marathon in a course record one hour nine minutes and 17 seconds.
The 36-year-old, using the event as preparation for the London Marathon on 25 April, beat American Deena Kastor by 26 seconds.
Mexican Madai Perez was a further two seconds behind in third.
Meanwhile, Zersenay Tadese, of Eritrea, struck 10 seconds from Sammy Wanjiru's three-year-old world record to win the Lisbon Half Marathon in 58:22.
Four-time world half marathon champion Tadese, 28, beat Kenyan pair Sammy Kitwara (1:00:03) and Duncan Kibet (1:00:21), earning 50,000 euros (£45,000) for surpassing Wanjiru's mark which was set in The Hague in 2007.
Yamauchi, whose personal best over 13.1 miles is 1:08:29, only returned to racing in February after recovering from a foot injury which ruled her out of last year's World Championships in Berlin.
"I'm still not back at my very best but I'm getting there," she said.
Japan-based Yamauchi had to reel in Kastor after the 2004 Olympic marathon bronze-medallist and 2006 London Marathon winner had built up a 200-metre lead with only two miles remaining.
"When Deena went away, I thought if I could make the top three that would be okay," added Yamauchi, who finished second in last year's London Marathon in a personal best time of 2:23:12.
"When she came back in sight I thought 'wait a minute, this race isn't over'."
Kenya's Peter Kamais ran 59:52 to win the men's race in the Big Apple, 46 seconds ahead of countryman Moses Kigen-Kipkosgei, with American Mohammed Trafeh third in 1:00:40.
Double Olympic champion Haile Gebrselassie failed to finish after suffering an asthma attack.