Shane Lowry is just three shots off the clubhouse lead after the first round at the weather-affected Andalucia Masters.
A thunderstorm delayed the start of play by two hours and another in early afternoon led to a further suspension of play which meant half the 126-strong field did not complete their rounds.
Lowry hit five birdies to card a 69. Padraig Harrington and Gavin Moynihan were both level par through nine holes.
Tournament host Sergio Garcia made an excellent start to his bid for a third-straight victory.
Garcia has finished outside the top 10 just once in 13 previous appearances at Valderrama and an opening 68 left him two shots off the mark set by England's Ashley Chesters.
Chesters carded six birdies and a solitary bogey in a five-under-par 66 which gave him a one-shot lead over France's Gregory Bourdy, with Australia's Jason Scrivener alongside Garcia on three under.
Bourdy needs to finish joint second or better to retain his European Tour card after failing to record a top-30 finish all season.
The 36-year-old is 179th on the money list, with the top 116 at the end of the week securing full playing privileges for next season.
"It was nice," Garcia told Sky Sports after his first round since becoming the top points scorer in Ryder Cup history in Europe's victory at Le Golf National in Paris.
"Obviously I didn't feel as smooth when I came back from the break. I hit a great shot on six, unfortunately missed that birdie putt and then hit a couple of loose shots, but any time you shoot under par on this course, it doesn't matter the conditions, I'm obviously happy about it.
"I saw a lot of great things, a couple of things that we need to improve but overall it was a good day.
"To be here at my favourite golf course to play, where I'm a member from last year onwards, it's great fun and hopefully we'll get a little bit lucky. It doesn't look like the weather is going to be very helpful but it would be nice to get as many rounds as possible."