American Ernst closed on Sunday with an eight-under 63 to be 20-under 193 for the week, good enough for a two-shot win over Anna Nordqvist.

Four strokes behind Nordqvist entering the round, Ernst had the best score of the day, making 10 birdies and two bogeys at Pinnacle Country Club.

She joined 2014 champion Stacy Lewis as the event's only American winners.

Swede Nordqvist closed with a 69 after opening with rounds of 64 and 62 to take a three-shot lead into the final day.

FINAL LEADERBOARD

Kirk was tied-for seventh at 14-under after a 66 on Sunday which included an eagle at the par-5 7th and birdies at 5, 14, 15 and 17.

The experienced Australian's previous best showing in 2020 was a share of 22nd.

Minjee Lee had seven birdies in her six-under 65 to end her week at nine-under a share of 28th.

Ernst opened with consecutive 65s to put herself in position to win for the first time since the 2014 Portland Classic.

Angela Stanford (65) and Nelly Korda (67) tied for third at 16-under.

Jenny Shin (68) and Sei Young Kim (69) were 15 under to share fifth.

Alexa Pano, the 16-year-old Florida amateur playing on a sponsor exemption, finished in a tie for 41st.