Trick 7		North Q♣ w
Declarer (W) ♠ - A 10 9 8 6 ♥ - A 10 5 ♦ - A K 3 ♣ - A 3	> 3♣		9♣	Dummy (E) ♠ - K Q J 7 3 ♥ - K J 3 ♦ - Q J 10 ♣ - 9 2
		4♣ South		Won = 6 Lost = 1

Declarer leads his 3♣ to deliberately put one of the Opponents on lead. This is an important play technique called a "throw in".
For look what happens next ?