Beijing: Britain`s Olympic champion Jessica Ennis-Hill began her quest for a second world heptathlon title by leading through the first two events on Saturday`s opening day in Beijing.
Making her return to major competition after giving birth last year and a battle with niggling injuries, Ennis-Hill will carry a slender 30-point advantage over fellow Briton Katarina Johnson-Thompson into the evening session.
Gold medallist at the 2009 world championships, Ennis-Hill clocked 12.91 seconds in her 100 metres hurdles heat in blazing sunshine at the Bird`s Nest stadium before clearing a season`s-best 1.86 metres in the high jump.
Ennis-Hill goes into the shot put and 200m later in the day with 2,192 points but feeling pressure from Johnson-Thompson, who was facing her countrywoman for the first time since the former ran away with the 2012 London Olympic title.
Johnson-Thompson set a personal best of 13.37sec in the 100m hurdles before sailing over at 1.89m in the high jump and just failing at 1.92, which would have been an outdoor best for the Liverpool-born 22-year-old.
American Barbara Nwaba suffered a painful start to the championships, meanwhile, smashing into the second hurdle and bravely picking herself before crumpling in a heap once more after hitting the fourth with a fierce thud.