Telegraph Prize Puzzle - Cryptic Connections Puzzle - September 13 Deadline

[Matakari]

Good day,
I'm stuck on # 3 of the 5 clues. Your help, please!
Thanks in advance !

3. Course that's looked for by expanding business? (9)

[geevo41]

Newmarket

[Matakari]

Thanks very much, geevo41!

[Matakari]

Impossible to find the word or phrase from the unused letters: ACDGKMPQTU to link the answers to the five clues.
Any help from anybody?
Thanks again!

[dannyk13]

Card games

[JJ109]

Card Games ??

[dannyk13]

You have an 'i' missing, one of the answers is Piquet

[fiction-factory]

^and an E missing then

[dannyk13]

Soory FF ignore my post about Piquet. Card games is the correct answqer.

[dannyk13]

In this puzzle all the letters of all the answers are given. Matakari has obviously crossed off some wrong letters.

[Matakari]

Where did I go wrong?
My answers for the 5 clues are the following:
CHEAT, EREIRA, NEWMARKET, MODLINEK, PONTOON from:
1. Talk about European crook (5)
2. Anger ahead of time for one on track? (6)
3. Course that's looked for by expanding business? (9)
4. Lone kid upset after 1000 rush once here (8)
5. Exciting, no top on in boat (7)
Thanks again for coming to the rescue, dannyk13 and geevo41!

[sedge47]

2 is Pique t
4 is K londike

[fiction-factory]

Yes, Pique+t.
I can see why you went for EREIRA though- anagram of IRE in ERA, although I don't think there is an anagram indicator

[fiction-factory]

And I assume the track reference refers to Nelson Piquet

[fiction-factory]

There is an Ereira trail though - bike trail/track- just to confuse things further.
But Piquet is far better and correct

[Matakari]

Many thanks to you all! Everything falls into place now.