Lu Xiuzhi (left), silver medal, and Liu Hong, gold medal, after the women's 20 km walk event.
Liu Hong won the women's 20 kilometres walk on Friday to hand China its first gold medal of the Beijing world championships, as defending champion Ashton Eaton took control of the decathlon.
The morning after Usain Bolt's emphatic 200m win at the Bird's Nest stadium, Liu gave home fans something to cheer when she headed a Chinese one-two in the walk with "little sister" Lu Xiuzhi.
The pair broke early and built up a massive lead in Beijing's scorching morning heat, with Liu coming home for gold in one hour 27.45 minutes with Lu right behind her. Ukraine's Lyudmyla Olyanovska took bronze, 28 seconds behind.
"There was a lot of pressure but I was confident in this mission," said Liu, who added that she had struck a pact with Lu, her junior by seven years, not to race each other in the final kilometres.
"When we hit the front at the start I didn't think we were going that quick but nobody followed us, so we just carried on. It's a dream to win the gold."
After the US medal tally was boosted on Thursday by golds from triple jumper Christian Taylor and 400m runner Allyson Felix, it was another of their star athletes who took to the Bird's Nest on Friday in the shape of multi-discipline specialist Eaton.
The world record-holder and defending champion, also reigning Olympic and two-time world indoor champion, timed 10.23sec in the opening 100m before leaping a best of 7.88m in the long jump, both leading performances.
Eaton, whose Canadian wife Brianne Theisen Eaton claimed silver behind Jessica Ennis-Hill in the women's heptathlon, then managed a best of 14.53m in the shot put to leave him on 2,830 points. Canadian Damian Warner sat in second with 2,747 with Germany's Rico Freimuth third (2,730).
Elsewhere in the field, Ukraine's Andriy Protsenko and Russian Olympic champion Ivan Ukhov both missed out on advancing to the final of the high jump, to be held on the ninth and last day of competition on Sunday.
Ashton Eaton from the U.S. reacts after the 400m event of the men's decathlon during the 15th IAAF World Championships at the National Stadium in Beijing, China August 28, 2015. REUTERS/Lucy Nicholson