Peterborough United are off to Wembley after winning the JPT Southern Area Final.
After a 2-2 draw at London Road, Swindon took a 32nd minute lead through Pritchard but Peterborough levelled through Britt Assombalonga in the 75th minute.
With the score at 1-1, the match went to penalties. Swindon missed the first penalty. Posh scored and had the advantage until Danny Swanson had his kick saved.
Reis missed Swindon's fifth kick leaving Tommy Rowe to score and send Peterborough to Wembley to play either Chesterfield or Fleetwood on March 30th.