'Unlucky, unlucky, unlucky,' she said, describing her shot sequence. 'It was bad.'
Yet Pressel birdied the next hole, and gained a stroke here and there to climb back up the leaderboard.
She capped the day with a 25-foot putt from the fringe on the 18th hole to grab a share of the lead going into Sunday's final round. Pressel finished the second round Saturday with a 69 for a 7-under 137 at Columbia-Edgewater Golf Club. She joins Jenna Daniels, Jeong Jang and Candie Kung on top.
'This is the best I've played in a while,' said the 18-year-old Pressel, who won the U.S. Women's Amateur last year.
Six others were one stroke off the pace at 6 under on the par-72, 6,327 course near Portland International Airport.
Daniels had a 1-under 71 on Saturday. She bogeyed her first three holes, but recovered with the help of six birdies -- including a key one on No. 17 after a tee shot into the trees.
'I knew I needed to keep it below the limb (in front of her), but above the limb close to the green,' she said. 'I couldn't have hit it any better.'
Kung shot a 66 while Jang had a 68 in a threesome with Allison Hanna. The two pals pushed each other.
'She's a great player,' Kung said of Jang. 'I have fun with her.'
Juli Inkster had one of the best rounds Saturday with a 67 to put her at 6 under. She noted that with so many players finishing well, Sunday could be anyone's day.
'I'm not even on the leaderboard, so people can kind of pop up and you don't even know about them,' she said.
Indeed, Inkster's name was not on the big scoreboard on the No. 18.
Pat Hurst had a 69 to join the 6-under group. She could have finished in better position, but bogeyed her final two holes.
'I had two 3-putts coming in, so it's a little disappointing,' she said. 'But overall, I'm hitting the ball good, and I'm looking forward to (Sunday).'
Christina Kim, playing in Hurst's threesome, was also in contention at 6 under after a second-round 72.
Kim, one of the most colorful players on the tour, would have liked a better day.
'I am where I am. The only thing I could do at this point would be to go out and start screaming in the middle of people's backswings,' she joked, adding quickly, 'and I wouldn't do that.'
Rookie Jee Young Lee, the leader after the first day, tumbled Saturday with a 3-over 75 and wrapped up at 5 under.
The defending champion is South Korean Soo-Yun Kang, who earned her only LPGA victory in Portland. Kang withdrew after nine holes on Saturday because of a neck injury.
Ashley Prange, who won a place in the tournament with her victory in The Golf Channel's 'The Big Break V: Hawaii,' didn't make the cut, with a two-day finish at plus 10.
Because of the show, Prange also earned expenses to compete on the Futures Tour, where she has won twice. She ranks fourth on the tour's money list with two events to go: The top five money winners on that tour get to play on the LPGA Tour next season.
'Obviously I'd like to have played better, but it was a major learning week for me on what I need to do in the next two weeks to get my game ready, and then also next year to hopefully get my game ready to be out here,' she said.
Annika Sorenstam, who won in Portland in 2002 and '03, was taking some time off after winning the Scandinavian TPC, the tournament she sponsors. Sorenstam also skipped last year's Safeway Classic.
The Golf Channel will televise the Safeway Classic starting at 10 p.m. ET Friday.