PINEHURST, N.C. — Lucy Li’s historic United States Women’s Open debut was marred by two double bogeys and a triple bogey, which she handled with equanimity. The most disappointment Li showed all day was after her round of eight-over-par 78, when she had to hand over her pink ice-cream bar to her aunt to answer a videographer’s interview questions.

The 11-year-old Li, the youngest girl ever to qualify for the tournament, did the preteen set proud Thursday with her poise and performance on the 6,296-yard Pinehurst No. 2 layout. Her score left her well behind the leader, the two-time major winner and top-ranked Stacy Lewis, who carded a bogey-free 67.

But Li won many friends and no doubt influenced several pony-tailed girls walking alongside their fathers in her 200-strong gallery, easily the largest of the morning wave.

“It was a lot of fun,” Li said. “I kind of struggled today, but it was great.”

She was standing on a box that U.S.G.A. officials positioned in front of the microphone stand to give Li, who is listed at 5 feet 2 inches, a boost. She was wearing a patriotic outfit she picked out for the occasion: a shirt with red and white horizontal stripes and a blue square on her chest filled with white hearts and a red-white-and-blue, knee-length skirt with silver sequined stars.