Rachel Hetherington and Karrie Webb lead a group of seven players one stroke behind the five leaders. They were joined at minus-5 by Brandie Burton, Pat Hurst, Meena Lee, Helen Alfredsson, Michele Redman, Lara Tadiotto and Nadina Taylor.
Annika Sorenstam returned to action for the first time since the Women's British Open. She carded a 3-under-par 69 and stands in a tie for 27th. She started on the back nine and parred her first 12 holes, before picking up three birdies in her last six holes to end three shots off the pace.
Matthew, who turned 36 on Thursday, started on the back nine and opened with a 6-foot birdie putt on No. 10. She made it two straight when she knocked her third to the par-5 11th within 2 feet.
The two-time Solheim Cup performer made another 6-foot birdie putt on the 12th to make it three in a row. Matthew bogeyed the par-3 15th, but came right back with a birdie on 16.
Matthew made the turn at minus-4 after sinking a 15-foot birdie try on 18. She birdied the fifth and seventh, but stumbled to a bogey on the eighth. The Scotland native knocked her third to the par-5 ninth to tap-in range to share the lead.
'I got off to a perfect start,' said Matthew. 'I birdied the first three holes. It's just great when you're defending and start well and be in contention again.'
Daly-Donofrio birdied the first, third and fifth to quickly move to minus-3. She dropped in back-to-back birdies from the eighth to get to 5 under.
The two-time winner on the LPGA Tour bogeyed the 11th, but got that stroke back with a birdie on 12. Daly-Donofrio sank an 8-foot birdie try on 13, but slipped to a bogey at the next. She erased that mistake with a birdie on the 16th before she parred the last two holes.
'It's a great place to be, the top of the leaderboard,' Daly-Donofrio said. 'You can never win a tournament on the first day, but you certainly can play your way out of a tournament on the first day. It's just a very easy, steady round today.'
Baena birdied each of the first two holes from within 6 feet. She then two-putted for birdie at four. The 28-year-old drained an 8-foot birdie putt on eight and two-putted for birdie on nine to turn at minus-five.
After a bogey on 10, Baena birdied 11 and 15 to share the lead.
Marti started on the back nine and posted birdies at 12 and 17. Around the turn, she ran in a 13-foot birdie putt on the third. The Spaniard got up and down for birdie at the fourth. She birdied eight and two-putted for birdie on nine to close a bogey-free round.
'It definitely was a nice day. I haven't had a good round for a long time,' said Marti. 'I just played very good golf today. I didn't miss a fairway, I didn't miss a green.'
Kang knocked her second shot to 3 feet at the first and kicked that in for birdie. She stuck her wedge within 2 feet at the fourth to get to minus-2. However, Kang three-putted for bogey at six, but got that stroke back with an 8-foot birdie putt at the eighth.
The Korean chipped in for eagle on the ninth to jump to 4 under. Around the turn, Kang birdied the 10th from 10 feet out and the 16th from 6 feet for a share of the lead.
Mi Hyun Kim, the 2000 runner-up and 2002 champion, and Hee-Won Han, the 2003 winner and last year's runner-up, each carded 4-under-par 68s. They were joined there by Cristie Kerr, 2003 Kraft Nabisco champion Patricia Meunier-Lebouc, Women's British Open winner Jeong Jang, Angela Jerman, Amy Hung, Karen Weiss, two-time winner this season Paula Creamer, Giulia Sergas, Sae-Hee Son and Sherri Steinhauer.