Two holes later, Sorenstam answered. And then again at the par-4 16th, rolling in a birdie putt from about 8 feet away after Ochoa briefly drew even with a tap-in from an inch.
So it went Friday in the Michelob Ultra Open, where sometimes driving rain and two rain delays did little to put a damper on a friendly duel between the game's best players.
Sorenstam followed a 64 with a 66, leaving her at 12 under, three better than Ochoa, whose bogey at the last hole gave her 68, and Jeong Jang, who matched Sorenstam with her 66.
"I'm right there, so I'm excited," Ochoa said.
The day wasn't as good for Michelle Wie. Playing in her first tournament in 2 1/2 months, the Stanford freshman followed a 4-over 75 with a 71 and missed the cut by four strokes.
"I just feel really rusty," she said after making a birdie on the final hole to finish even on the day. "I feel like I just need to play more. ... I feel like I can get it back."
Twelve strokes off the pace at the start of the day, Wie took a backseat to the pairing that had Ochoa, Sorenstam and defending champion Suzann Pettersen playing together. Several thousand fans were waiting for them either at the 10th tee, where they started, or along the fairway, hoping to see the start of a battle classically reserved for weekends on the tour.
Ochoa, who has won half of the first 10 events so far this season, upped the ante when she rolled in a 15-foot birdie putt on the first hole, No. 10, celebrating with a fist pump.
But Sorenstam was better, again going bogey-free over the 6,315-yard River Course.
"I can't remember the last time that was but, you know, anything can really happen on this course," she said of one of the few courses where she hasn't won. "I'm just trying to play smart. I'm trying to play, you know, conservative at times and aggressive at other times."
And the fans were into it all the way, braving the often difficult conditions.
During their round, one woman shouted "Viva Mexico!" right before Ochoa backed away from a 5-foot birdie putt, then stepped up and missed it. When Sorenstam hit her 50-yard third shot on the par-4 ninth hole to 3 feet, a man called out "Nice shot, Annika. Welcome back."
