Simone Biles booked her place in all four apparatus finals but the United States were overshadowed by the team representing the Russian Olympic Committee in women's team gymnastics qualifying in Tokyo.
Biles won four gold medals in Rio in 2016 and is in a strong position to repeat the feat as she topped the list of qualifiers for the all-around final and also achieved the leading individual score on vault.
But a series of uncharacteristic stumbles elsewhere meant the defending champions trailed in second place at the end of the session, while Great Britain qualified for the team final in sixth place.
Biles said: "Obviously there are little things we need to work on, so we'll go back and practise and work on that, just so we can do our best performance at team finals, because that's what matters."
Sixteen-year-old twins Jennifer and Jessica Gadirova booked their respective places in the all-around final, whilst the latter also qualified for the individual floor final in fifth place.
Jessica Gadirova said: "I'm speechless. It was incredible and there are so many words that I don't even know that could just describe how I'm feeling.
"An Olympian at 16 is like, 'what the hell?' – it's just so crazy to even think I could be an Olympian this young, just to have the dream of using that word and being under the Olympic rings and competing at the highest level."
