PORTLAND, Ore. — Brooke Henderson is trying to leave everyone else behind — and not get too far ahead of herself.

The 17-year-old Canadian took the outright lead in an LPGA Tour event for the third time this year, birdieing three of her last four holes Friday for a 5-under 67 and a one-shot advantage in the Cambia Portland Classic.

“Just to stay within myself and play my own game,” she said when asked what she has learned this season. “Playing as an amateur I was used to a lot of people, a lot of media and television and stuff like that, but it’s a little bit different on the LPGA Tour, and I think that’s something that I’ve gotten a lot more comfortable with this year.

“I think if I can just stay patient and play my own game and not focus on outside factors, I think good things will happen.

Playing in cool, breezy and sometimes wet conditions, Henderson finished with an 8-foot birdie putt on the par-4 ninth to reach 11-under 133 at Columbia Edgewater. She made her only bogey of the tournament at 11, but rebounded with birdies at 12, 14 and 3 before the late burst.

Henderson, who turns 18 in September, has made $466,818 in nine LPGA Tour tournaments and needs to finish in the top 40 on the money list to earn a card for next year. LPGA Tour Commissioner Mike Whan denied Henderson’s age petition last year, preventing her from playing Q-school. She earned a spot in the field in Monday qualifying.