Knuth, 21, playing in only her fifth tournament as a professional, hit eight birdies to lead by one stroke from the Australian Karen Lunn, the British Open champion, who shares second place with Sweden's Liselotte Neumann and Karina Orum, from Denmark.
Laura Davies, winner of her fifth title of the year in the Irish Open last weekend, struggled on the greens but is in a chasing pack on 69 which includes Scotland's Dale Reid.
'I putted well but didn't hole anything. You get days like that but I only missed two greens and I drove well which was the key to my score,' Davies said after her round.
Davies holed from 12 and eight feet for birdies at the sixth and 18th holes and a couple of two-putt birdies came at the long ninth and 10th holes.Reuse content