Tim Bury (8-2) allowed four runs on nine hits in 7 2/3 innings to pick up the win for UD. Burny Mitchem picked up his sixth save in 1 1/3 innings of hitless relief.
Shortstop Brian Blasik, a three-time All-Atlantic 10 honoree, had two hits, including a leadoff home run in the first, scored four runs and had two RBIs to lead the UD offense.
Ian Hundley also collected two hits for the Flyers, who took advantage of six Richmond errors to build a 7-1 lead.
UD (30-28) will face Richmond or No. 1 Saint Louis at 12 p.m. today in the title game, which will be televised nationally by the CBS Sports Network.
Richmond and Saint Louis faced off late Friday night in the consolation final. The Spiders or Billikens would have to beat the Flyers twice today to win the double-elmination tournament.