Grace Park and Hee-Won Han share fourth place at 4-under-par 67.
Killeen began her day on the back side of the River Course at Kingsmill Golf Club. She burst out of the gate by rolling in a 15-foot birdie at the 10th. Killeen followed that up with an eight-foot birdie putt at the next.
Killeen, who is searching for her first win on the LPGA Tour, birdied the par-5 15th and later stuck a wedge within four feet at the 18th to setup another birdie.
On the front side, she dropped a shot on the par-3 second after a poor chip but recovered with a two-putt birdie at the next. However, Killeen could not maintain the momentum as she bogeyed the par-4 fourth when she was unable to get up-and-down for par.
'I hit bad shots on Nos. 2 and 5. I was fortunate to recover on the next hole,' said Killeen. 'I had a lot five- and six-footers for birdies so that's always nice.'
Killeen came right back again as she knocked a 6-iron to five feet at the par-3 sixth to setup another birdie. She rolled in a four-footer for birdie at the par-5 seventh for her final birdie of the round.
'You have to hit it in the fairways and you have to hit a lot of greens.' Killeen said. 'I was fortunate today that I also seemed to make a lot of putts.'
Sergas also began her round on the back nine. She got off to a good start with a birdie at the par-4 12th but dropped a shot on the par-4 14th when she three-putted from the fringe.
Sergas got going again late on her first nine. She notched back-to-back birdies from the 17th to make the turn at minus-2.
Around the turn, Sergas rolled in a birdie at the first from 15 feet. She followed that with another birdie, this one at the par-5 third. Sergas continued the roll at the par-5 seventh with an up-and-down birdie.
Sergas lost her chance at solo first when her par putt lipped out on the eighth. She did recover that stroke at the ninth, her last, after she knocked an 8-iron within three feet.
'I knew I could play good,' said Sergas, who shot the best round of her professional career. 'The more nervous I get, the more it's not going to come. But today, was just a good day.'
Ochoa also got going on the back nine. She sank a two-footer for birdie at the 13th to start a run of three straight birdies.
On the front side, Ochoa birdied the par-5 third from five feet out and capped a bogey-free round with her final birdie at the eighth.
Annika Sorenstam returned to action this week with a 3-under-par 68. She is tied for sixth place with Akiko Fukushima, Karen Stupples and Suzann Pettersen.
LPGA Teaching and Club Professional member Suzy Whaley carded a 6-over-par round of 77. Whaley, the winner of the 2002 Golf for Women LPGA T&CP National Championship, is competing via a sponsors exemption. She will be also compete on the PGA Tour later this year at the Greater Hartford Open, where she qualified by winning a sectional qualifier.