Trick 1.

Tricks AB, 0
YZ, 1
1. A↷ Y B Z
4♠, 5♠, 9♠, 10♠

Trick 2.

Tricks AB, 0
YZ, 2
2. A Y B Z↷
Kg♠, A♠, 7♠, Qn♠

Remark (Trick 2).—Z's better play would be to open the heart suit.

Trick 3.