Shanghai - World champions David Oliver and Shelly-Ann Fraser-Pryce said Saturday they were taking nothing for granted despite heading into their title defences this season in good form.
Oliver, the 110m hurdles title holder, and triple sprint champion Fraser-Pryce said they were pleased with their progress as they geared up towards the World Athletics Championships in Beijing in August.
But the pair said form can go out of the window in the big tournaments as they prepared to meet their greatest rivals at Sunday's Diamond League gathering in Shanghai.
"It is just all about the race, who is going to get a good rhythm going into that," said US hurdler Oliver, looking forward his title defence in the Chinese capital.
The 33-year-old will face compatriots Aries Merritt -- the Olympic champion and world record holder -- and 2011 world champion Jason Richardson at the Shanghai meet.
Oliver said he was racing badly in 2013 ahead of the Moscow world championships, adding: "It did not have any bearing on what happened a couple of months later."
He said his form was "going pretty well" during the early stages of this season, but was far from complacent about victory in Shanghai.
"It doesn't really matter what happened beforehand. It is all about taking care of business in the present," he said.
"So I am just trying to go out there and have a great performance."
Fraser-Pryce will be competing in her first 100m of the season in Shanghai, but she produced her best 200m since 2013 racing in her home nation of Jamaica last week, a result which she said gave her a huge boost.
"I think I will do pretty well (in Shanghai)," Fraser-Pryce said. I am looking forward to (the) 100m and I know it will be great."
Fraser-Pryce was a triple gold medallist in Moscow, winning titles in the 100m, 200m and the 4x100m relay.
In Shanghai, the 100m Olympic champion will be facing highly-decorated Jamaican Veronica Campbell-Brown, who is expected to pose the greatest threat to her world crown in Beijing.
Nonetheless she said victory over her great sprint rival in Shanghai would not give her a psychological edge at this summer's showdown.
"If I win tomorrow then it is not very significant for winning in August," the 28-year-old said.
"Because the field is still young and there are many people at different stages of their training so you can never know what can happen."