Lewis had birdied the par-4 17th at Yalong Bay Golf Club to move into the outright lead, but her dropped shot at the last saw her finish on five under par, alongside Thai duo Thidapa Suwannapura and Pavarisa Yoktuan.
There is a group of five players on four under comprising Sweden’s Isabella Ramsay, Norwegian Tonje Daffinrud, China’s Yan-Hong Pan, Malaysia’s Ainil Bakar and Kusuma Meechai of Thailand.
A further six players are on 69, including Finland’s Ursula Wikstrom, England’s Holly Clyburn and French Solheim Cup player Gwladys Nocera.
World No.6 Shanshan Feng and the defending champion Xiyu Lin of China both carded opening 70s and are in a tie for 15th on two under par.
Feng had a slow start to her first appearance in the event, but was relatively happy to be three shots from the lead.
She said: “I would say overall I did okay. Two under is not a super good score, but it’s not bad. My problem today was not hitting the balls close to the pins so I didn’t have that many birdie chances, but I still made three, and a bogey on a par-5. I still have two more days, so more chances.”
Feng won the Buick Championship in Shanghai in May. This is her fifth start on the Ladies European Tour in 2015 and she is trying to win the Order of Merit, which she is currently leading by close to €79,000 over Denmark’s Nicole Broch Larsen, who won the Helsingborg Open.
The 22-year-old Dane is still within reach after an opening round of level par 72 and said: “It was a good score considering I hit two balls in the water and made a three-putt on number three. I made an up and down for par on the seventh, but I was struggling a bit on the back nine with my approach shots and couldn’t get close to the pins.”
She and Lewis are both making their first appearance in the Sanya Ladies Open. Lewis, a fourth year Ladies European Tour and LPGA player from Jacksonville, Florida, whose best finish was second at the 2013 New Zealand Open, said: “I love it here. I think it’s my favourite tournament in China. I played Blue Bay last week as well, but I really like this place.
“I hit my fairways and greens and had a lot of putts for birdie. I made a few and it was an easy, kind of a boring day. My caddie and I clicked with the numbers, my irons were good and I was sticking my shots close. I played two really good up and downs and didn’t have to force anything. I’ve gone through some swing changes and caddie changes and I’ve learned so much this year.”
Lewis enjoys being able to combine playing on the LPGA and LET. “I like having both. I would be done with my season if I wasn’t playing LET, so I like having these events to play in going into the off-season. I love it out here, I love LET. It’s a very relaxed environment and I love playing on it,” she said.