If the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) comes as a suprise to a defender, it might be twice as much of a hassle if it is delivered at blitz speed. The following game is over in little more than a few eyeblinks, with a vision of the enemy Queen as the last thing that the Black King saw before checking out.
TrustyPawn - taviman
blitz
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
, FICS, 2009
4...Kxf7 5.d4 exd4 6.e5 Nge7 7.Ng5+ Kf8 8.Qf3+ Kg8 9.Qf7 checkmate