Australian surfing great Stephanie Gilmore has knocked reigning world champion Caity Simmers out of the Gold Coast Pro. Competing in the World Surf League for the first time in nearly two years, Gilmore is through to the quarter-finals after beating the American on Thursday in the round of 16. Competition resumed after a three-day break and Gilmore, the eight-time world champion, edged out the world No.2 12.84 to 12.50. Gilmore is competing at Burleigh Heads as a wildcard and she will face Canadian Erin Brooks in the quarters. Isabella Nichols, who won the previous round at Bells Beach, will go up against fellow Australian Sally Fitzgibbons in another quarter. Compatriot Molly Picklum is also through to the last eight, while world No.1 Gabriela Bryan joined Simmers as a big-name casualty when she lost her heat to Brazilian young gun Luana Silva. The men are halfway through their round of 32 heats and Australian Ethan Ewing was knocked out by compatriot Morgan Cibilic.