The 22-year-old, the only player from China on the tour, had the lowest round of the tournament at the right time and finished at 6-under 282.
“I am so excited right now,” Feng said. “I did it!”
Stacy Lewis, bidding to win her third consecutive stroke-play event on the LPGA Tour, shot 70 to tie for second with Mika Miyazato, Suzann Pettersen and third-round leader Eun-Hee Ji. Miyazato shot 69, Pettersen 70, and Ji 72.
Karrie Webb, who started the day one shot behind Ji, had 72 to finish at 3-under. Little-known Gerina Piller, a star in college at UTEP, and Ai Miyazato each had a closing 68 to also finish at 3-under.
Paula Creamer had 71, and Giulia Sergas and Inbee Park shot 72 to finish another shot back.
Defending champion Yani Tseng had a closing 76 and was 13-over in a tournament she won a year ago by 10 shots.
CHAMPIONS TOUR: In Birmingham, Ala., Tom Lehman successfully defended his title in the Regions Tradition, finishing the
major with 4-under 68 for a two-stroke victory.
Lehman overcame a near-constant drizzle and occasional heavy rain at Shoal Creek – plus hard charges by Bernhard Langer and Chien Soon Lu – for his sixth Champions Tour victory.
Lehman finished at 14-under 275. Langer and Lu shot 66 to tie for second.
Lehman, the former British Open champion who shot in the 60s all four days, joined Jack Nicklaus, Gil Morgan and Fred Funk as the only players to win the Tradition multiple times.
CURTIS CUP: In Nairn, Scotland, Britain-Ireland rallied to beat the United States 10½-9½ in the Curtis Cup, ending the Americans’ 16-year domination of the biennial women’s amateur matches.
Northern Ireland’s Stephanie Meadow scored the critical point, beating Amy Anderson 4 and 2 in the seventh of the eight singles matches.
Britain-Ireland and Europe now hold the Curtis Cup, the men’s Walker Cup, plus the Ryder Cup and Solheim Cup.
The United States leads the series 27-7-3.
NATIONWIDE TOUR: In Leon, Mexico, Lee Williams won the Mexico Open for his first Nationwide Tour title, closing with 2-under 70 for a one-stroke victory over Paul Haley II.
Williams, a former Auburn player, finished at 14-under 274 at El Bosque and earned $112,500.
Aiken’s Matt Hendrix shot 73 and tied for sixth at 278. Augusta’s Scott Parel shot 73 and tied for 29th at 285.