Gail Devers’ unprecedented drive for the double continued with a comfortable 7.88 win, the fastest of the morning’s four opening round races.
The 37-year-old Californian, who was the first to win the double US titles since Chi Cheng of Taiwan turned the trick in 1970, was in front before the second hurdle and eased considerably after gliding over the last.
Behind her, Nicole Ramalalanirina of France, the 2001 bronze medallist, was second with a seasonal best 7.93, with Romanian champion Carmen Zamfir third in 7.96 for her first sub-eight performance.
Lacena Golding-Clarke won the first heat in 7.90, with Linda Ferga-Khodadin of France close behind in 7.91. Spaniard Aliuska Lopez was third in 8.01. For Khodadin and Lopez, their early morning performances were seasonal bests.
World outdoor champion Perdita Felicien led from the gun to win heat two in 7.91, with American indoor runner-up Joanna Hayes second in 8.01. Russian Natalya Kresova was next in 8.06.
Susanna Kallur won the final heat handily, clocking 7.91, ahead of Jamaican Delloreen Ennis-London (8.00). Second Russian entrant Irina Shevchenko was third in 8.02, knocking four one-hundredths from her personal best. Kallur’s twin sister Jenny, was fourth in the first heat, and advanced on time.
The only minor surprise of the first round was Spain’s Glory Alozie, the reigning European outdoor champion, who finished fifth (8.08) in the final heat, failing to advance.
The semi-finals are at 16:30, with the final an hour later.