(AFP) - Suzann Pettersen fired a bogey-free eight-under 64 on Friday to seize a share of the lead with defending champion Brooke Henderson at the halfway stage of the Portland Classic.
"I sure did find some magic on the greens today," said Pettersen, whose round is her lowest of the year.
The 15-time LPGA Tour winner has had a relatively quiet season so far, posting just three top-10s.
She is looking for her first victory of the season. Her last win came at the 2015 Manulife Classic.
"I maybe gave away a shot or two towards the end. I tried to take advantage of little softer greens this morning," said Pettersen, who shot a 69 on Thursday and is level with Canada's Henderson at 11-under 133.
First-round leader Henderson was mistake-free through her first 16 holes on Friday, compiling 12 pars and four birdies on the Columbia Edgewater Country Club course in Portland, Oregon.
The Canadian teenager recovered from her lone bogey of the day at 17 with a birdie on the final hole.
Colombia's Mariajo Uribe sits alone in third place at 134 after a 67.
Henderson, 18, has been one of the busiest and most successful LPGA golfers this season. She has played 17 of 18 tournaments and missed just one cut so far.
"I think I've had some kind of high points and low points over the last seven-week stretch." Henderson said.
"I like to play a lot, though. I considered taking a week off, then like what am I going to do?
"I am just going to go home and practise. I might as well go and play and just conserve energy where I can and just try and focus on the things that I need to."
Pettersen says her hard work is also starting to pay off. She needed just 24 putts on Friday.
"I feel like when I putt well I can put up a good score. Today I felt like I could make anything," she said.
"It's starting to show results. I'm excited for my game to come around. I am just trying and go out and play another two great rounds and then see where it takes me."
Angela Stanford (71), Austin Ernst (66) and Sweden's Pernilla Lindberg (68) share fourth place at 138.