Gal had five birdies in her round, which was the second to last match of the day. Her three-under round was enough to put her ahead of South Korean Kim Song-Hee and American Angela Stanford.
"It's only the first day, but I'm delighted to be at the top," said the 24-year-old, who is ranked number 69 in the world.
Michelle Wie was also in contention with a one over par 73 and seventh overall, but the world's number one female golfer, Lorena Ochoa, struggled to come up with three-over round of 75. Defending champion Shin Ji-Yai had to settle for 77.
Angela Stanford showed some skill on the putting greens, by sinking a monster putt on the seventh hole for an eagle three.
Michelle Wie, while playing well, was still looking for her first victory on the tour, which she needs to get a place on the Solheim Cup.
"The wind was tough and any score under par today was exceptional," said Wie. "I'm used to it blowing in Hawaii, but here it is 30 degrees colder."
France's Gwladys Nocera, last year's European number one had a miserable day and put a couple of eights on her score card to finish the first day with an embarrassing round of 91, a huge 19 over par.
"It was just a really bad day," said the Frenchwoman.
