Gilmore scored 12 to beat compatriot Amee Donohue (11.16) and Pauline Ado of France (5.03) on Wednesday to go through to the third round of the Rip Curl Pro Search event in Peniche.
Gilmore’s Brazilian rival Silvana Lima, who has won the last two rounds of the world tour, finished second in her round to also progress to round three.
Gilmore is the two-time defending world champion, but Lima has improved noticeably in the opening three rounds this year to put more pressure on the Australian.
Hawaiian world No.4 Melanie Bartels starred in the one-metre swell at the backup site of Belgas.
She had the best ride of the round, an eight, and the highest heat score of 13.17.
But world No.3 Sofia Mulanovich of Peru was a surprise opening-round loser and she must now go through round two.
Australian Chelsea Hedges scored 11.33 to win their heat and compatriot Jessi Miley-Dyer was second with 9.84, relegating Mulanovich (8.03) to third.
The women have waited since Monday for their event to start and they were scheduled to go ahead as soon as the men’s Pro Search finished on Wednesday morning at the main Supertubes site.
But deteriorating conditions forced organisers to delay the women until noon as they shifted to Belgas, an isolated beach about 10km outside Peniche.
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