We now travel to the Liberty Stadium for the replay against Carlos Carvalhal’s Premier League side on February 27 with a place in the last eight at stake.
Wednesday might have snatched a late winner when Adam Reach cut inside but crossed, rather than shooting, and just failed to find Lucas Joao, who was also ruled marginally offside.
Reach went close early on and we had the better of the first half, Swansea’s biggest threat coming when Cameron Dawson pulled off a fine tipover save to deny Mike van der Hoorn’s close-range header.
The Swans showed more intent and aggression in the second period but we kept them at bay and, at the other end, Atdhe Nuhiu went close before that late break from Reach which finished in disappointment.
Dawson, Hunt, Venancio, Pudil, Fox, Reach, Butterfield (Pelupessy 70), Jones, Boyd, Wallace (Joao 80), Nuhiu.