Procedure:

1. Ask a volunteer to pick a card from the deck, memorize it and then put it back on top of the deck.
2. Bring the deck behind your back, turn over the top card, so that the card the spectator selected is face up while the rest of the deck is still facing down.
3. Bring the deck back to your front and ask the volunteer if the card at the bottom is the card selected.
4. While doing this, you are actually looking right at the card the spectator had chosen. The spectator will certainly say "No, that’s not the one", bring the deck behind your back again and flip over the volunteer's card so all the cards are now facing down.
5. Do some light shuffling with the deck, and bring it back to the front and ask if the bottom card is the one the spectator had selected. Since it definitely is not the chosen card, and you will probably be looking like a retard on stage, act like you did screw up the trick.
6. Now, let the spectator shuffle the deck, directly take out the card that was chosen and baffle your audience.