Laura Davies had a poor final round

"I played defensive golf," Sorenstam said.

"I didn't want to make mistakes. I would have played more aggressive had someone made a big move."

Mhairi McKay, with a 69, and Johanna Head, with 71, were the top Britons in joint fourth place on nine under.

But Laura Davies slipped from second to seventh with a disappointing 76, putting her eighth in the Solheim Cup rankings.

Sorenstam is assured of making the European team for Minneapolis next month after her eighth win of the season, and Gustafson is almost certain to join her.

The top seven will be named in the team after this week's WPGA Championship of Europe at Royal Porthcawl.

Final scores from Compaq Open (Gbr and Irl unless stated):

271 Annika Sorenstam (Swe) 67 66 68 70
275 Sophie Gustafson (Swe) 67 70 72 66
278 Ana Belen Sanchez (Spa) 70 72 68 68
279 Mhairi McKay 71 74 65 69, Johanna Head 68 70 70 71
282 Nadina Taylor (Aus) 70 68 74 70
283 Laura Davies 70 71 66 76
284 Suzann Pettersen (Nor) 71 68 74 71, Catrin Nilsmark (Swe) 70 71 71 72, Sara Beautell (Spa) 72 72 68 72, Elisabeth Esterl (Ger) 71 67 72 74