Kerr finished tied for fifth at the Women's British Open, five strokes behind tournament champion Yani Tseng. Combined with Ai Miyazato's tie for ninth, Kerr's result allowed her to move from third to second in the rankings.
Miyazato slipped from second to third while Jiyai Shin retained the No. 1 ranking and Suzann Pettersen, who tied with Shin for 14th in the British event, kept the No. 4 spot.
Tseng is still No. 5 and Choi Na-yeon, who tied for third, is sixth and Paula Creamer remained seventh.
The Top 10 golfers did well at the Women's British Open, with only two finishing worse than a tie for 21st. Anna Nordqvist went from eighth to ninth, trading places with Kim Song-hee, after tying for 69th in the tournament. Karrie Webb, who tied for 43rd, fell from 10th to 11th, as Kim In-kyung, who tied Choi for third, moved to 10th from the No. 11 spot.