Suzann Pettersen has made it back-to-back wins on the LPGA Tour after she held off a determined challenge from 16-year-old New Zealand amateur Lydia Ko at the Evian Championship.

The 32-year-old Norwegian, winner of the Safeway Classic in Oregon two weeks ago, shot a final round 68 for 10 under par 203 in a Championship that had major status for a first time but had to be reduced to 54 holes due to weather problems.

Pettersen, collecting her second major, received a cheque for 350,000 ($A506,000) and finished two ahead of second place Ko, who closed with a 70 for eight under.

“It’s great to win another major and this one has definitely been well worth waiting for,” said Pettersen.

“I was actually really nervous coming down the stretch and even nearly played up short at the 18th (a par four over water). But I said to my caddie I had to go for it and it worked out.”

Ko, already a four time winner alongside the professionals, was one off the lead overnight but led on her own after she nearly holed her second shot and had an easy birdie three at the opening hole.

A three-putt bogey at the short second set her back and Pettersen, a star of last month’s European Solheim Cup victory, then took the lead for the first time with a key 25-foot birdie putt at the eighth.

At the long 13th, Ko drove into a bunker and then failed to get up and down from the side of the green and a Pettersen par edged the more experienced player two in front.

There was a late scare for Pettersen when she drove into trees and had to chip out sideways at the par four 17th.

But a third to four feet to save par was another killer blow.

For Ko, who refuses to divulge when she will join the paid ranks, it was another astonishing performance.

Just last month, she retained the Canadian Open.

“It has been a great week,” she said.

“I didn’t take all my chances but Suzann played really well.”