Pair tied for the lead
Maria Hjorth of Sweden and the USA's Michele Redman both shot six-under-par 66s to share the lead after the first round of the Longs Drugs Challenge.
The pair hit seven birdies each to lead by a shot from Korean In-Kyung Kim and Hjorth's compatriot Michaela Parmlid.
England's Laura Davies and Becky Morgan of Wales led the British charge and were tied on two under par with world No 1 Lorena Ochoa.
Longs Drugs Challenge
| First-round leaderboard | | | |
| Blackhawk Country Club, par 72 | | | |
| -6 | M Hjorth | Swe | 66 |
| -6 | M Redman | USA | 66 |
| -5 | I-K Kim | Kor | 67 |
| -5 | M Parmlid | Swe | 67 |
| Selected others | | | |
| -4 | S Pettersen | Nor | 68 |
| -2 | L Davies | Eng | 70 |
| -2 | B Morgan | Wal | 70 |
| -2 | L Ochoa | Mex | 70 |
| -1 | K Stupples | Eng | 71 |