At the Molineux, Strand Larsen’s quickfire brace overturned a deficit after West Ham had fought back from 1-0 down. His second, in the 88th minute, ensured Wolves avoided extra time and knocked out Graham Potter's men.
The night’s biggest shock came at the Stadium of Light, where third-tier Huddersfield dumped out Sunderland. The visitors struck inside nine minutes, but were pegged back by a late Marc Guiu equaliser. In the shootout, 19-year-old Milan Aleksic missed the decisive kick as the Terriers triumphed.
Leeds also departed on spot-kicks, Sheffield Wednesday progressing from 12 yards after a 1-1 draw. Burnley, meanwhile, saw off Championship side Derby 2-1 to keep Scott Parker's side in the hat.
Elsewhere, Brentford prevailed in the all-Premier League clash at Bournemouth, scoring twice before the hosts were reduced to 10 men in added time.
Wrexham produced another memorable cup night by edging Preston 3-2.
Results
Reading 2-1 AFC Wimbledon
Cambridge United 3-1 Charlton
Wolves 3-2 West Ham
Acc Stanley 0-2 Doncaster Rovers
Barnsley 2-1 Rotherham
Birmingham 0-1 Port Vale
Bournemouth 0-2 Brentford
Bromley 1-1 Wycombe (WYC win 5-4 on pens)
Burnley 2-1 Derby
Burton 0-1 Lincoln
Cardiff 3-0 Cheltenham
Millwall 2-1 Coventry
Norwich 0-3 Southampton
Preston 2-3 Wrexham
Stoke 0-3 Bradford City
Sunderland 1-1 Huddersfield (HUD win 6-5 on pens)
Swansea 1-1 Plymouth (SWA win 5-3 on pens)
Wigan 1-0 Stockport
Sheff Wednesday 1-1 Leeds (WED win 3-0 on pens)