Only Sarah Hardcastle had reached a women's final in Atlanta, but the 19-year-old from Newcastle matched that in the first event of the opening day. Rolph finished sixth in the 100m freestyle final - falling 0.02sec short of her personal best - having moved up one place from the heats when she had the seventh-fastest time.
"I have proved to people I am a world-class swimmer," she said. "I've improved from 16th at the last Olympics to sixth in these worlds in just one and a half years."
Victory went to America's five-times Olympic gold medallist Jenny Thompson. China's world No1, Shan Ying, won bronze.
Fears that Chinese swimmers would be booed and barracked when collecting their medals never materialised as the Australian crowd reacted with polite applause when Shan was handed her medal.
Palmer's attempt to add to his European gold from Seville failed as he finished seventh in a final won by a local swimmer, Michael Klim. Palmer had reached the final with the sixth-fastest time, having headed for home in his heat lying eighth. The 23-year-old from Bath was last after the first 50m in the heat and stayed there until the last turn. He made up one place in the last 50m, but his time of 1:50.43 was well off his best.
"I was awful - there is nothing much more I think I can say," Palmer said. "I was swimming faster than that in training last week.
"The only consolation is this might augur well for the 400m, because it just felt like I did four easy-paced swims out there."