''I think you try to stay patient during the delay more than anything, and try to stay loose,'' Lewis said. ''I didn't sit down too much. Tried to stay up.''
Ko did the opposite.
''I sat down, had some chicken soup, played some cards,'' Ko said. ''I was totally relaxed.''
But she was careful to avoid hot chocolate.
''I had a cup of hot chocolate before during a delay and next hole I hit it out of bounds,'' Ko said. ''My mom brought me a cup and I was like, `Oh, that better not be hot chocolate.'''
Lewis overcame rain and hail to take the second-round lead, shooting her second straight 3-under 69 at Lake Merced. Winless since the Women's British Open in August, the third-ranked Lewis had a one-stroke lead over Ko and first-round leader Karine Icher.
''We all went into the day knowing it would play hard,'' said Lewis, who has five runner-up finishes since her victory at St. Andrews. ''''It was a test of patience. I took it one shot at a time and wanted to get the ball into the hole as fast as I could. Fortunately, I was able to do that.''
Ko had a 71, and Icher followed her opening 66 with a 73.
Lewis and Ko played alongside Michelle Wie, dealing with heavy rain and hail that suspended play for just over an hour. Play resumed in steady drizzle that gave way to sunny afternoon conditions that helped several of the late starters.
Wie, the winner last week in Hawaii, was even par after her second 72.
The weather wavered between a slight mist and light shower before pounding the course just after noon, forcing the suspension at 12:36 p.m.
''I honestly thought we'd get it done,'' Lewis said. ''Then we got to seven and it just poured. We had to call off Lydia from her putt when it started to hail.''
Ko, who turned 17 on Thursday and was named among TIME magazine's 100 most influential people, thought she could get her putt in before being called off.
''I was crazy and out of my mind thinking about putting in the hail,'' Ko said. ''It started getting dark and I'm glad I was called off.''
Ko returned to the course and made the putt.
Icher was tied for the lead with Lewis at 5 under when the horn sounded.
''I ate a little and dried my clothes,'' Icher said. ''Rain delays are never fun but it happens. Being in the top five to start the tournament is pretty good, definitely my best start this year.''
''It was a very good putting day and I hit a lot of fairways,'' Park said. ''I got a little lucky with the weather. I only had to play in the rain for four holes.''
Miyazato finished before the delay.
''The golf course was more challenging,'' Miyazato said. ''I needed better course management.''
Second-ranked Suzann Pettersen, returning from a since back injury that sidelined her for three tournaments, was 2 under after a 72.