The 28-year-old made her history defining moment in her native China, closing out the Blue Bay LPGA event with a final-round of 70 and becoming the first player to claim successive victories this season on tour.
Feng opened the final round with a birdie at the par-4 1 and looked set to cruise towards her ninth Tour win before Jutanugarn compiled four birdies and a bogey over a six hole stretch to make the turn in three-under-par and take the lead by one from Feng.
The 28-year-old Feng's victory in her home country was celebrated by the fans and her fellow Chinese golfers, who showered her with water on the 18th green.
Feng, who also captured last week's TOTO Japan Classic title, added: "Hopefully there will be more Chinese getting on the tours and more world number ones coming up from China".
When Feng notched her second straight win at Blue Bay on Saturday, Park tied for third place while Ryu sat out.
She told LPGA.com: "I'm really, really excited and very proud of myself and I think it's special because I won this tournament to become world number one".
"I just want 2017 to keep going", said Feng said.
Moriya quickly rebounded at the next, sinking a six-foot downhill putt for birdie as Feng missed a four-footer and had to settle for par.
Feng, the 2016 Rio Games bronze medallist, now boasts nine LPGA Tour victories, one of them a Major.
As well as being China's first number one, she was also the country's first victor on the LPGA Tour (2012 Wegman's LPGA Championship). "A never-ending 2017, that would be great", Feng said.
Feng was surrounded by her compatriots after securing par and the win at the 72nd hole.
"Of course everybody is cheering for her". There's one more event, and I get to go home.
"However, that didn't happen because I didn't realize that actually the par putt that I was facing could be so, so, so important, and I was really nervous, especially on the half a yard, I was a little bit nervous, even shivering. I'm really enjoying this week so far".
South Korean Park Sung-hyun, who became the new world No. 1 on Tuesday, closed with even-par 72 to finish equal third with South African Ashleigh Buhai (73) and Americans Megan Khang (68) and Jessica Korda (71) at five strokes back.
The 2017 LPGA season will wrap up this week at the CME Group Tour Championship.