U.S. Solheim Cup teammates Juli Inkster and Christina Kim share second place after both shot a 5-under 67 in their first rounds at the Magnolia Grove Golf Course.
Neumann, who qualified for the tournament with a win at last year's Asahi Ryokuken International Championship, took the overnight lead with a bogey-free round that included six birdies in her final 12 holes.
After stringing together six straight pars, the 39-year-old Swede reached red numbers with a 4-foot birdie putt at the seventh -- one of just four birdies carded at the par-4 hole.
Neumann rolled in a 21-foot birdie putt at the par-4 ninth to make the turn at minus-2. Her next three birdie putts were much shorter -- two from 3 feet and one from eight -- until she pitched within 12 feet to set up her last birdie at 18.
'I think my eyes were totally the key today,' said Neumann. 'I really hit some good shots into the greens.'
Neumann has five top-10 finishes this season, including a third-place tie at the Longs Drugs Challenge last month. She hit 11 of 14 fairways and found 16 of the 18 greens in regulation during her round Thursday.
'It was just a good solid round, not any mistakes at all out there,' said Neumann. 'Just one of those days.'
Kim mixed six birdies with one bogey to reach 5 under. Ever the fiery competitor, she finished off her round with two birdies on her final three holes, rolling in an 8-foot putt at the 18th to get within one of Neumann.
'I'm just going to keep going like I have, stay aggressive,' said Kim. 'If I end up first or I end up 43rd, I just want to know that I didn't leave anything out there.'
Like Neumann, Inkster carded a bogey-free round. She made the turn at minus-2 and ended the day with three birdies on the last five holes.
'I felt like I stroked the ball well, and that's all you can ask,' said Inkster, who has played just 17 events this year.
Sharing sixth place at 3-under 69 are Candie Kung, Hee-Won Han, Rachel Hetherington and Lorena Ochoa. Reigning U.S. Women's Open champion Birdie Kim teed off first in the 43-player field and completed a solo round at 2-under 70 to share 10th place with six other players, including Rookie of the Year Paula Creamer.
The field for this tournament includes winners from the past four seasons as well as active LPGA Tour and World Golf Halls of Fame members. The participating players own a combined 222 LPGA victories.
Annika Sorenstam, a nine-time winner on tour this season, is skipping the event for a third straight year.