Webb carded a 4-under-par 68 in drizzly morning conditions for a one-shot advantage over the Swedish duo of Asa Gottmo and Helena Svensson. Australians Michelle Ellis and Wendy Doolan were among seven players tied with 2-under 70s.
'It wasn't too bad, I didn't get into too much trouble out there,' said Webb, who won here in 2000.
After starting her day with seven straight pars from the 10th to the 16th, Webb posted a birdie at the 17th before adding another two pars. She dropped her only shot at the par-3 third but rebounded from the bogey with three birdies over her last six holes.
'I missed a couple of greens in the first couple of holes and made some good pars, where, if I didn't get up and down, those two holes would have changed the whole mood of the round,' said Webb, currently second behind Sorenstam in the world golf rankings. 'I wasn't really comfortable until three quarters of the way around and I made the most of it, I got the job done.'
Sorenstam is in Hawaii set to compete in the Takefuji Classic, the season-opening event on the 2002 LPGA Tour.
Sweden's Maria Hjorth and Aussie Rachel Teske finished the first 18 holes tied with three others at 1-under. Jan Stephenson, who began her professional career with a victory at the 1973 Australian Open, a title she also won in 1977, headlined a group of six golfers at even-par 72.
Two other stars in the field, England's Laura Davies and defending champion Sophie Gustafson of Sweden, both closed well but were six strokes off the pace with two-over 74s. Davies battled back from a shaky round to eagle the last hole, while Gustafson finished strong with three consecutive birdies.