The Canaries were rewarded with an equaliser on 78 minutes when Josip Drmic bundled the ball in after
Spurs goalkeeper Michel Vorm had spilled a long-range effort from Kenny McLean.
Norwich defender Ben Godfrey cleared Serge Aurier's effort off the line as the tie went to extra-time.
Spurs boss Jose Mourinho sent on teenage Republic of Ireland forward Troy Parrott towards the end of the
first period, but neither side could find a breakthrough.
In the penalty shoot-out, Vorm redeemed himself with an early stop from McLean only for Erik Lamela to
hit the crossbar.
It was Krul, though, who took centre stage as he saved from Parrott and, after Todd Cantwell had coolly
converted, the Dutchman kept out Gedson Fernandes' effort as Norwich won the shoot-out 3-2.
The draw for the quarter-finals was made while the tie at the Tottenham Hotspur Stadium was heading into
extra-time.
Norwich's reward will be a home fixture against either Derby or Manchester United, who play on Thursday
night.
Earlier, Sergio Aguero had fired holders Manchester City into the quarter-finals with a 1-0 win at Sheffield
Wednesday.
City - who lifted the Carabao Cup with victory over Aston Villa at Wembley on Sunday - will be away at
Newcastle in last eight.
Troy Parrott missed from the penalty spot
(Getty)After a low-key opening at Hillsborough, it was the Premier League side who broke the deadlock early in
the second half.
Aguero drilled the ball past Owls keeper Joe Wildsmith in the 53rd minute, the striker appearing marginally
offside when taking Benjamin Mendy's pass into the penalty area.
Owls substitute Steven Fletcher just failed to connect at the far post with a low cross through the City
penalty area as the Sky Bet Championship side saw their cup run come to an end.
Leicester beat Birmingham 1-0 with a late goal at the King Power Stadium to book their place in the
quarter-finals, where they will host Chelsea, who had knocked out Premier League leaders Liverpool on
Tuesday night.
The Foxes saw a long-range effort from James Maddison clip the top of the crossbar and then had the ball in
the net in the second half through Kelechi Iheanacho - but the offside flag had already gone up.