(Photo credit: Erik Williams-Imagn Images)

LPGA Tour rookie Akie Iwai shook off an early bogey to shoot 9-under par over the final 16 holes Saturday to storm to the 54-hole lead at the Standard Portland (Ore.) Classic.

Starting the day tied for fourth at the Columbia Edgewater Country Club, the 23-year-old native of Japan shot an 8-under 64 -- tied for the low round of the tournament -- to sit at 18-under 198 for the three rounds and carry a two-stroke lead into Sunday.

Australia's Grace Kim shot a 5-under 67 and sits second at 16-under 200, with Sweden's Linn Grant sitting one shot behind Kim after making a charge with a 7-under 65.

Iwai, who has never won on Tour but has a pair of runner-up finishes earlier this season, bogeyed the par-3 second hole Saturday but followed that with three birdies and an eagle over the next five holes. She opened the back nine with three birdies over the first four holes, then made four straight pars before closing her round with a birdie on 18.

After her round, Iwai credited one hole in particular for sparking her big run.

'No. 5, (the) par 5, I made eagle,' she said of the hole that started a three-hole burst in which she went 4 under. 'After I got many birdie chances, (I rode) good tempo.'

While Iwai got hot early, Kim was middling at 1 under on her round through 13 holes before finishing her round birdie-birdie-par-eagle-par.

The eagle came the par-4 17th, when her approach from the right rough hit the rough to the right of the hole, then bounced left on the green and then rode the break into the hole.

'Yeah, I leaked my drive a little right. I thought I was going to be in the rough, which it was,' Kim said. '(The approach) leaked right again. I was like, 'Oh, please get through the rough.' Somehow went in the hole, so I guess a little bit of luck in there.'

Gurleen Kaur shot a 2-under 70 and sits in fourth at 13 under, one stroke ahead of Aditi Ashok of India (65) and Gina Kim (67).

Jeongeun Lee5, who began the day with a one-stroke lead over Kaur and Grace Kim, carded a 2-over 74 to fall into a tie for 11th at 10-under 206.

One of those in pursuit of Iwai, whose last top 10 finish was a tie for seventh at the Meijer LPGA Classic in June, is her twin sister Chisato Iwai, a fellow rookie who shot a 6-under 66 and is tied for seventh at 11 under.

Like her sister, Chisato Iwai eagled the par-5 fifth and birdied the par-5 seventh. She bogeyed the par-3 13th but followed that with back-to-back birdies and closed with a birdie 3 on 18.

Tied with Chisato Iwai at 11 under are fellow Japanese player Rio Takeda (66), Lauren Coughlin (66) and South Korea's Haeran Ryu (67).

--Field Level Media