Home hope Vitor Lopes maintained his narrow advantage at the Open de Portugal as high winds and the threat of lightning forced a delay to the second round.
Only 27 groups were able to tee off at Royal Obidos because of the lengthy weather-related delays, with Lopes managing only three holes.
A dropped shot on the second hole put him back to six under par, one shot clear of South Africa's Garrick Higgo, who was one under through six holes when play was stopped, and Spain’s Carlos Pigem.
Pigem is one of a number of players who are yet to begin their second round.
Gavin Moynihan leads the Irish contingent on two over.