Ariya Jutanugarn will take a commanding four-stroke lead into the final round of the U.S. Women's Open after a gruelling outing on Saturday.

Jutanugarn had to play 28 holes after the second round was suspended due to dangerous weather on Friday but the Thai star managed to end the day atop the leaderboard, ahead of Sarah Jane Smith at 12 under following a 67.

The 2016 Women's British Open champion was only through eight holes in her second round when play was halted at the Shoal Creek Golf and Country Club in Alabama.

Jutanugarn resumed at 6:45am (local time) and posted a 70 before she carded a third-round 67, which included six birdies and a bogey.

"I think I'm going to sleep well tonight. I didn't sleep much last night and I'm really tired. I just want to go out and be proud of myself every day," Jutanugarn said.

"I'm pretty sure tomorrow is going to be a pretty good day. I don't know what the outcome will be, but I know what I'm going to take action on."

Smith – winless in 222 LPGA Tour stars – ended Friday's weather-delayed round four strokes clear but the Australian's 74 saw her lead vanish on day three.

Kim Hyo-Joo (68) is two strokes further back, a shot ahead of fellow South Korean Kim Ji-hyun (70).

Inbee Park (71) is four under heading into the final round, while Michelle Wie's 76 saw her drop to one over.