Davies, whose career includes 79 tournament wins, was joined at the top of the leaderboard by Bath's Henrietta Zuel and Lydia Hall of Bridgend.
Davies shot seven birdies in her round despite suffering from an injured Achilles tendon which had prevented her from playing a practice round.
Davies told ladieseuropeantour.com: "It's a lovely golf course - I knew I liked it. Seven birdies and one bogey is a very satisfactory day."
Zuel also shot seven birdies and one bogey to stay in the hunt for her maiden Ladies European Tour title along with Hall.
Stacey Keating and Stacy Lee Bregman shared fourth place on five under, with Joanna Klatten, Beth Allen, Lee-Anne Pace and Carin Koch one stroke further behind, while 16-year-old English amateur Charley Hull was in a group on two-under.
Collated first-round scores (Eng unless stated, par 72):
66 Laura Davies, Henrietta Zuel, Lydia Hall (Wal)
67 Stacey Keating (Aus), Stacy Lee Bregman (Rsa)
68 Joanna Klatten (Fra), Beth Allen (USA), Lee-Anne Pace (Rsa), Carin Koch (Swe)
69 Tandi Cuningham (Rsa), Gwladys Nocera (Fra), Ashleigh Simon (Rsa), Melissa Reid, Trish Johnson, Adriana Zwanck (Spa), Kiran Matharu
70 Dawn Shockley (USA), Kirsty S Taylor, Diana Luna (Ita), Holly Aitchison, Charley Hull, Carlota Ciganda (Spa), Nontaya Srisawang (Tha), Rebecca Codd (Irl), Caroline Afonso (Fra), Klara Spilkova (Cze), Sophie Sandolo (Ita), Julie Greciet (Fra)
71 Mikaela Parmlid (Swe), Rebecca Artis (Aus), Steffi Kirchmayr (Ger), Lisa Holm Sorensen (Den), Marjet Van Der Graaff (Ned), Tania Elosegui (Spa), Kylie Walker (Sco), Carly Booth (Sco), Hannah Burke, Kyra Van Leeuwen (Ned)
72 Frances Bondad (Aus), Malene Jorgensen (Den), Louise Larsson (Swe), Stefanie Michl (Aut), Rachel Bailey (Aus), Connie Chen (Rsa), Elizabeth Bennett, Esther Choe (USA), Cassandra Kirkland (Fra), Laurette Maritz (Rsa), Lucie Andre (Fra), Sophie Giquel-Bettan (Fra), Caroline Martens (Nor)
73 Karen Lunn (Aus), Danielle Montgomery, Liebelei Lawrence (Lux), Clare Queen (Sco), Caroline Westrup (Swe), Lynn Kenny (Sco), Alison Whitaker (Aus), Sophie Walker, Barbara Genuini (Fra), Bree Arthur (Aus)
74 Jenni Kuosa (Fin), Ursula Wikstrom (Fin), Stephanie Na (Aus), Piyathida Ployumsri (Tha), Elisabeth Esterl (Ger), Sara Wikstrom (Swe), Eleanor Givens, Xi Yu Lin (Chn), Sahra Hassan (Wal), Anja Monke (Ger), Elena Giraud (Fra), Sharmila Nicollet (Ind), Veronica Zorzi (Ita), Lynnette Brooky (Nzl), Jade Schaeffer (Fra), Mireia Prat (Spa)
75 Elin Emanuelsson (Swe), Rachel Jennings, Anais Maggetti (Swi), Linda Wessberg (Swe), Marieke Nivard (Ned), Maria Beautell (Spa), Claire Aitken, Charlotte Ellis, Lucy Williams, Stefania Croce (Ita), Holly Clyburn, Rebecca Hudson
76 Zuzana Kamasova (Svk), Marianne Skarpnord (Nor), Miriam Nagl (Ger), Alexandra Vilatte (Fra), Kym Larratt, Nikki Garrett (Aus), Maria Ohlsson (Swe), Anne-Lise Caudal (Fra), Felicity Johnson, Sara Djos (Swe), Florentyna Parker, Celine Palomar (Fra), Amy Boulden (Wal), Sofia Harkonen (Fin), Julie Maisongrosse (Fra)
77 Titiya Plucksataporn (Tha), Rachel Drummond, Jessica Yadloczky (USA), Yu Yang Zhang (Chn)
78 Rachel Bell, Laura Cabanillas (Spa), Mary Mattson (USA), Charlie Douglass, Carmen Alonso (Spa), Caroline Rominger (Swi), Margherita Rigon (Ita), Becky Brewerton (Wal)
79 Virginie Lagoutte-Clement (Fra), Suzanne Dickens, Vikki Laing (Sco), Melodie Bourdy (Fra)
80 Monique Smit (Rsa), Georgina Simpson, Mianne Bagger (Den)
81 Chrisje De Vries (Ned), Xin Ying Wang (Chn)
82 Tara Dayer-Smith
83 Danielle Mcveigh (Irl)