Albin Countergambit, Lasker Trap

The Lasker Trap is a chess opening trap in the Albin Countergambit, named after Emanuel Lasker, although it was first noted by Serafino Dubois . It is unusual in that it features an underpromotion as early as the seventh move.
Analysis.
1. d4 d5 2. c4 e5
3. dxe5 d4
4. e3
4... Bb4+ 5. Bd2 dxe3 (see diagram)
6. Bxb4??
6... exf2+
7. Ke2 fxg1=N+! (diagram)
8. Ke1 Qh4+ 9. Kd2
9... Nc6