Stacy Lewis claimed the World No. 1 women's golf ranking by firing a final-round eight-under par 64 to beat Japan's Ai Miyazato by three strokes on Sunday at the $1.5 million (RM4.7 million) LPGA Founders Cup.

The 28-year-old American knocked 2012 Founders Cup champion Yani Tseng of Taiwan from atop the rankings after a stay of 109 weeks with the victory and Tseng finishing in a share of 59th place, 19 strokes off the pace.

Lewis became only the second American woman golfer to claim the top spot, after Cristie Kerr in 2010, by making birdies on three of the last four holes while Miyazato, who led most of the way, took a double bogey at the 16th.

"It's unbelievable," Lewis said. "We were battling back and forth, and I didn't expect her to do that there. I was just trying to make birdies there at the end."

World No. 1 "has a pretty good ring to it," Lewis said just one day after taking a two-stroke penalty after her round when her caddie was penalized for testing a bunker.

"It was just fitting with everything that happened yesterday that I had my back against the wall again today," Lewis said.