Resignation after 11 moves

In a game of speed chess, my opponent resigned after my eleventh move. I forced his bishop to retreat, which took away the escape square for his rook. When it was clear he couldn't save his rook, he resigned. My opponent was Starianovea of South Korea, who played white. Here are the moves of the game along with my commentary:

1. e4 c5
2. Bc4 e6

White develops the bishop early. I play e6 so that I can later play d5.

3. e6 Nc6

Black prevents d5.

4. Nf3 a6
5. a4 f6

Black prevents b5.

6. exf Nxf6
7. d3 Be7
8. Bg5 0-0
9. Bxf6 Bxf6

Black's move is very committal. My bishop now has control of the f6-a1 diagonal.

10.  0-0 d5

I can play Bxb2, but I want to drive back the bishop so that the rook loses its only escape square.

11. Ba2 Bxb2

White blunders. He should play Bb3 to give his rook an escape square. By playing Bb3, he loses his rook.

Down a pawn and unable to save his rook, white resigns. His eleventh move leads to the loss of his rook and his ninth move gives me control of an important diagonal. In a difficult position, white decides to resign early.