However, it was a long and disappointing day for Britain's Laura Davies, who slumped to a 76 after a downpour flooded the greens and halted play for almost two hours around mid-day.
Lisa Hackney, Joanne Morley and Suzanne Strudwick led the British challenge with matching rounds of 70 with Strudwick carding five birdies after dropping two shots in her first three holes.
Davies made heavy weather of the par-five holes which cost her two bogeys and a double bogey at the final hole where she ran up a seven after driving into the trees before hitting her recovery into an unplayable lie.
HENNESSY CUP (Refrath, Cologne) Leading first-round scores (GB or Irl unless stated): 68 L Neumann (Swe), H Alfredsson (Swe), K Orum (Den). 70 S Strudwick, V Michaud (Fr), L Hackney, J Morley. 71 N Fink (Aut), T Johnson, S Gronberg, A Sorenstam (Swe), C Koch (Swe). 72 S Dallongeville (Fr). 73 M Lunn (Aus), L Navarro (Sp), T Fischer (Ger), C Duffy. 74 L Lambert (Aus), A-M Knight (Aus), A Rogers, M Koch (Ger), A Gottmo (Swe), D Reid.Reuse content