Woking took an early lead against Cheltenham, but the League Two side trounced them in extra time brought about by Steven Gillespie's equaliser.
Lloyd Blackman headed Woking in front when he got on the end of Jimmy Aggrey's cross on 18 minutes.
After Gillespie levelled, Grant McCann missed the chance to win it when Clint Davies saved his penalty.
Jamie Victory put Cheltenham ahead on 100 minutes, then Brian Wilson (two) and Craig Armstrong wrapped up the win.
Woking: Davies, El-Salahi, Aggrey, Watson (Murray 102), Selley, Liam Cockerill (McAllister 76), Evans, Ruby, Sam Cockerill,
Rawle, Blackman (Richards 76)
Subs Not Used: Jalal, Jackson
Goals: Blackman 18
Cheltenham: Higgs, Gill, Victory, Duff, Caines,
Finnigan (Bird 90), McCann, Armstrong, Melligan (Wilson 70),
Odejayi (Spencer 97), Gillespie
Subs Not Used: Guinan, Brown
Booked: Armstrong, Spencer
Goals: Gillespie 59, Victory 101, Wilson 112, Armstrong 117,
After Extra Time
Ref: G Hegley (Hertfordshire).