Springfield, IL (My Sportsbook) - Se Ri Pak and Jee Young Lee both fired rounds of six-under 66 on Thursday to share the lead at the LPGA State Farm Classic.

Kris Tamulis is a stroke further back at five-under 67 on a tight leaderboard at Panther Creek Country Club.

Including the co-leaders, 70 players are separated by only five shots at the top of the leaderboard -- including some of the top names on the LPGA Tour.

Natalie Gulbis, Suzann Pettersen and Anja Monke are tied at 68; while Paula Creamer, Yani Tseng, Morgan Pressel, Laura Davies and 2004 champion Cristie Kerr headline a large group at 69.

Pak, 31, rallied to catch Lee by making birdies at three of her final four holes.

She opened the round with a birdie at No. 1, set up by a sand-wedge to 15 feet. Pak made her only other birdie on the front nine when she holed a long putt at the sixth.

Making her move on the back nine, Pak rolled in a 15-footer for birdie at No. 10. She holed a 10-foot birdie putt at the 15th, two-putted for birdie at the 16th, then drained a 16-footer at the 18th to tie Lee for the lead.

Pak, a 24-time LPGA Tour champion, hasn't won since 2007 -- the same year she qualified to be the first Korean inducted into golf's Hall of Fame.

The five-time major champion hasn't finished better than 13th place in nine previous starts this season, but she said her game is settling down.

And it couldn't come at better time.

Next week is the second major of the season, the McDonald's LPGA Championship, which Pak has won three times.

"I'm very exciting about that happening," she said. "Overall, this is probably [a great time] to play well."

Lee set the pace by shooting her 66 in a morning threesome. Beginning at the 10th tee, she collected seven birdies against just one bogey for her round.

It marked the lowest score of the season thus far for the 23-year-old Korean, who hasn't won since she broke through at the 2005 CJ Nine Bridges Classic, when she was a member of the Korean LPGA.

Lee played on faster greens in her morning group. Like the rest of the field, she dealt with rough that was thicker than in years past.

"I hit it longer, so I can get out easy," said Lee.

Michelle Wie, still seeking her first LPGA Tour win, leads a large group tied at two-under 70. The 19-year-old bogeyed her final two holes, missing a chance to share third place.

Last year, Wie finished the third round in second place but was disqualified for not signing her scorecard before leaving the scoring area.

"It was a very unfortunate event. But, you know, I played very well. So I gained a lot of confidence from that," Wie reflected. "I probably won't do it again."

Defending champion Ji Young Oh opened with a two-over 74 and is tied for 108th place.