Former world No 1 Lydia Ko is two off the pace alongside Swedish duo Linnea Strom and Caroline Hedwall, while overnight co-leader Carlota Ciganda is in the group four back that contains Race to Costa del Sol leader Atthaya Thitikul and England's Hannah Burke.
Lydia Ko birdies the ninth to tie for the top on -8Highlights Second Round 2021 Saudi Ladies International
Hewson cancelled out an opening-hole birdie with a dropped shot at the fourth but then picked up a shot at the par-four sixth and posted back-to-back gains around the turn.
Three straight birdies from the 12th lifted Hewson within a shot of Nuutinen, who had set the clubhouse target after four birdies in a five-hole stretch helped her to a 65, only for Hewson to then finish with back-to-back gains and move one ahead.
Hedwall is within three of the lead despite a double-bogey at the par-five 13th and Strom fell to seven under after two bogeys on her back nine, while Ko mixed five birdies with three birdies to complete the trio in tied-third.
Ladies European Tour: Alice Hewson holds halfway lead at Aramco Ladies Saudi International
Alice Hewson, chasing a second Ladies European Tour title, holds a narrow halfway lead after mixing nine birdies with a lone bogey in a second-round 64
Alice Hewson produced a sparkling second round to take a one-shot lead into the weekend at the Ladies European Tour's Aramco Saudi Ladies International.
The 24-year-old birdied seven of her final 10 holes to close an eight-under 64 at Royal Greens Golf and Country Club, taking her to nine under and a shot clear of Finland's Sanna Nuutinen.
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