Published: Sep 11, 2011 12:57 AM EDT
Updated: Sep 11, 2011 6:30 AM EDT

ROGERS, Arkansas (AP) - Defending champion Yani Tseng shot a 4-under 67 on Saturday and Amy Yang had a 64 to share the second-round lead in the LPGA Tour's NW Arkansas Championship at 9 under.

The top-ranked Tseng, the LPGA Championship and Women's British Open winner, leads the tour with four victories this season and has seven overall wins this year.

"I think it's hard to not have pressure because, I mean, for sure I've got pressure tomorrow, defending champion and in the lead," Tseng said. "The kind of thing's going to be a little pressure, but I just want to enjoy that pressure. I know tomorrow, first couple holes going to be nervous. If I were not nervous, that would be a little weird, so I mean, I care."

Taylor Leon (67) was a stroke back and Stacy Lewis (69) was 7 under along with Cristie Kerr (66), Inbee Park (65) and Jin Young Pak (68).

Michelle Wie missed the cut with rounds of 78 and 72.

Tseng had six birdies and two bogeys on the Pinnacle Country Club course. She nearly aced the 160-yard 15th hole, hitting to 2 feet to set up a birdie. She played her back nine in 32.

"I worked on my tempo on the back nine," Tseng said. "I got a little too fast with my tempo, but I just keep to myself, keep focused, and actually back nine I got really lucky. I had a good bounce on No. 8, good bounce on No. 4 or 5, and I have a great up and down on par 3, so those three shots were important."

Yang is winless on the LPGA Tour. She eagled the par-5 seventh.

"Everything was good today," Yang said. "I was hitting the ball solid and hitting the putts solid. You know, from tee to green, I was playing good. I'm really happy about my game."

Paula Creamer (68) was 6 under along with Ai Miyazato (67), Morgan Pressel (68) and Belen Mozo (65).