Establish a lead in tennis (3,2)

I believe the answer is:

set up

I'm a little stuck... Click here to teach me more about this clue!

'establish' is the definition.
(I know that establish can be written as set up)

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for set up that I've seen before include "An arrangement designed to trap or cheat" , "Fool" , "Arrangement; trick" , "a useful situation at tennis?" , "advantageous position at Wimbledon?" .)

I've seen this clue in The Globe and Mail.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.