Pretended back in Tokyo Biles managed to claim perfect scores (10)
I believe the answer is:
ostensible
'pretended' is the definition.
(thesaurus)
'back in tokyo biles managed to claim perfect scores' is the wordplay.
'back in' indicates one should take the final letters (the 'back' of the word).
'managed' is an anagram indicator.
'to claim' is an insertion indicator (inserted letters are claimed or taken in).
'perfect scores' becomes 'tens' (I've seen this in another clue).
The last letter of 'tokyo' is 'o'.
'biles' anagrammed gives 'sible'.
'sible' going around 'tens' is 'stensible'.
'o'+'stensible'='OSTENSIBLE'
(Other definitions for ostensible that I've seen before include "Professed" , "Apparent" , "Apparently true" , "Manifest" , "Seeming" .)