Challenges of Haggard confronting obstacles (9)

I believe the answer is:

gauntlets

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

'challenges' is the definition.
(I know this)

'haggard confronting obstacles' is the wordplay.
'haggard' becomes 'gaunt' (synonyms).
'confronting obstacles' becomes 'lets' (I can't explain this - if you can you should give a lot more credence to this answer).
'gaunt'+'lets'='GAUNTLETS'

'of' acts as a link.

Can you help me to learn more?

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app