The 14-year-old Thompson, from Coral Springs, Fla., is trying to become the youngest winner in LPGA Tour history.
Marlene Hagge won the 1952 Sarasota Open 14 days after her 18th birthday and took the Bakersfield Open two months later, but both were 18-hole events.
Paula Creamer won the 2005 Sybase Classic at 18 years, 9 months to become the youngest winner of a full tournament.
Thompson, the sister of PGA Tour player Nicholas Thompson, won the 2008 U.S. Girls' Junior and tied for 34th in July in the U.S. Women's Open. She shot 65 on Thursday.
Thompson, who had four birdies and one bogey on Friday, is trying not to get ahead of herself.
"I'm an amateur, and I'm just going to look at it and just be like, 'Whatever,' " she said. "Because I just try to come into these and just play well. It's just good competition for me. Best in the world."
Ochoa (68), Laura Davies (65), Yani Tseng (63) and Giulia Sergas (65) matched Thompson at 10-under 134 on The Senator course at the Robert Trent Jones Golf Trail's Capitol Hill complex. Tseng matched the tournament record with her 63.
"It's lovely to see a young girl like that playing so well," said Davies, of Thompson. "It's good for all of us if she keeps that up."
CHAMPIONS TOUR: In Timonium, Md., Tom Watson shot a bogey-free 2-under-par 68 to take a two-shot lead over four players at the halfway point of the Senior Players Championship.
Watson made two birdies Friday, the second with a 50-foot putt on No. 13.
Seeking his first win of the year on the Champions Tour, the 60-year-old Watson is at 6-under 134.
Watson started the day tied for second with Jay Haas, one stroke behind leader Lonnie Nielsen. But while Watson was undaunted by the stiff breeze at Baltimore Country Club, Nielsen shot 73 and Haas carded 70.
The foursome behind Watson at 136 includes Craig Stadler, who fired 65, Haas, Bob Tway (68) and Mark Wiebe (67).
Bernhard Langer, who also shot 65, was tied with Loren Roberts (67) and John Cook (68) at 137.
Former Augustan Allen Doyle shot 70 and is at 142; Augusta native Larry Mize had 73 and is at 143.
EUROPEAN TOUR: In St. Andrews, Scotland, Rory McIlroy birdied the last two holes on the Old Course at St. Andrews for 7-under-par 65 and a share of the lead at the halfway stage of the Dunhill Links Championship.
He is at 11-under 133, along with Richie Ramsay (66), and Michael Hoey (66).
Former Augusta State golfer Oliver Wilson is three shots off the lead after 69-67--136.
The field of 168 golfers plays one round over each of the three courses being used for this championship -- the others are Carnoustie and Kingsbarns -- before the final round Sunday on the Old Course.
NATIONWIDE TOUR: In San Jacinto, Calif., Brian Stuard shot 4-under-par 67 and is tied for the lead in the Soboba Springs Classic as he tries to salvage his season.
Stuard, who is tied with Craig Bowden at 7-under 135, has one top-10 finish in 25 starts this season and has won $104,561.
Stuard and Bowden (68 on Friday) have a one-shot lead over three golfers: Josh Broadaway (66), J.J. Killen (67) and Garth Mulroy (68).
WOODS FIRST ATHLETE TO EARN $1 BILLION
Forbes says Tiger Woods has become the first athlete to surpass $1 billion in career earnings.
The magazine estimates that golf's top-ranked player crested the plateau when he earned $10 million for winning the FedEx Cup on Sunday.
Forbes reported on its Web site on Tuesday that Woods entered 2009 having earned $895 million since he joined the PGA Tour in 1996. Prize money, appearance fees, endorsement fees, bonuses and his golf course design business were calculated to have pushed him over $1 billion.
The magazine says former NBA great Michael Jordan and former Formula One driver Michael Schumacher, at $800 million and $700 million, respectively, are Woods' closest competition in career earnings.