Claudio Bravo was the hero as stuttering Manchester City needed penalties to see off hard-working Wolves and make the Carabao Cup quarter-finals.
Pep Guardiola's Premier League leaders hosted Nuno Espirito Santo's Sky Bet Championship table-toppers in a match that promised much but failed to deliver goals over 120 minutes.
Often-maligned Bravo saved City's blushes on several occasions during the match and proved the spot-kick hero, denying Alfred N'Diaye and Conor Coady as the hosts won the penalty shootout 4-1 after the game ended 0-0.
Displaced between the sticks by summer signing Ederson Moraes, this was just the Chilean's third appearance of the season and came as both sides made nine changes apiece.
Bravo produced several fine stops to deny Wolves when they ventured forwards, while Sergio Aguero tried and failed to become City's all-time top scorer.
The Argentina international did manage to find the net and secure progress with a cheeky Panenka at the end of a shootout, but it was the saves of N'Diaye and Coady's efforts that were key.