Anticipation supporting Oxford rowers perhaps, catching rivals in the end (9)
I believe the answer is:
Here is my best explanation:
'anticipation' is the definition.
('foresight' can be a synonym of 'anticipation')
'supporting oxford rowers perhaps catching rivals in the end' is the subsidiary indication.
'supporting' becomes 'for'.
'oxford rowers perhaps' becomes 'eight' (a rowing crew can be called an eight).
'catching' indicates putting letters inside.
'in the end' says to take the final letters.
The last letter of 'rivals' is 's'.
'eight' going around 's' is 'esight'.
(Other definitions for foresight that I've seen before include "Anticipation", "anticipation", "power", "Power of prediction", "Clairvoyance", "Vision", "Ability to anticipate", "Prudence", "Prescience" and "Caution".)