The win was the third in the last four years and sixth in the last nine years for the Falcons, who now own the NCAA Division III record for most championships.
Blossey, a senior, was allowed to enter the shootout under NCAA rules, which permit any rostered player to take part in the penalty kicks.
Blossey blocked shots from Stevens' Jason Nachman, Peter Bednarsky and Jeremy Lippel to end the session after only three rounds.
Impossible? Not according to Blossey.
"I did dream about this," he said. "Actually, I had many dreams. After I realized that my role this year would be as a backup, I dreamed about us getting into the NCAA Tournament, or national championship, and it going to PKs. In a way, I feel guilty. It's almost as if I wished this upon us. But I was 100 percent enthusiastic to help the team win. We always talk about needing every single guy on the team to win a national championship. I knew coming in what I needed to do."
Jared Clugston started in goal for Messiah.
"Bloss is a great shot stopper," said Messiah head coach Dave Brandt. "[Clugston[ has attributes that serve him well, so we've went with him in game play. We had waffled on who we would go with if we went to PKs. It's cold, Bloss had been standing around for two hours, but we felt if it happened today we were going with Bloss."
The title was "probably the most unlikely of the six," according to Brandt. Besides the shootout in the final, Messiah played three other games in the postseason, winning all three on a golden goal. The Falcons beat Rochester, 1-0, in the second round. Their only comfortable win was 3-0 over Loras in the semifinals.
Dec. 5 in Greensboro, N.C.
Messiah 3 Loras 0. Goals: N.Thompson (Pezon) 12, D.Thompson (Mull) 51, Sanders (Pezon) 71.
Messiah -- Clugston, Cunningham, Binger, Overholt, Mull, Pezon, Compton, N.Thompson, Black, D.Thompson, Ramirez. Subs: Faro, Jeschke, Lee, Sanders, Todd, Renko, Rinker.
Loras -- DuBois, Minkel, Jennings, Hoyt, Lamale, Mejia, Rizzo, Filipiak, Bonilla, Crosby, McCord. Subs: Berndt, Strumpf, St. George, Johnson.
Referee: Mike Salyers.
Dec. 5 in Greensboro, N.C.
Stevens Institute 4 Amherst 1. Goals: Sheridan 4, Johnson (Faustino) 17, Johnson 53, Lockhart (Johnson) 78; Duker (Lynch) 77).
Stevens Institute -- Carr, Faustino, Nachman, Williams, Montalvo, Sheridan, Moquin, Bednarsky, Sandberg, Lippel, Johnson. Subs: DeFaria, Bowman, Lockhart.
Amherst -- Kovacs, Holland, O'Connor, Skayne, Genco, Lewis, Lynch, Rothkopf, Heo, Duker, Mooney. Subs: Grover, Addison, Connolly, Tsatimpe, Kelley, Linsmayer,
Referee: Scott Johnson.
Dec. 6 in Greensboro, N.C.
Messiah 1 Stevens Institute 1 (Messiah wins 3-0 on penalties). Goals: D.Thompson (Pezon) 3; Lippel 80.
Messiah -- Clugston, Cunningham, Binger, Overholt, Mull, Pezon, Compton, N.Thompson, Black, D.Thompson, Ramirez. Subs: Faro, Jeschke, Lee, Sanders, Gondwe, Sipe, Todd, Blossey.
Stevens Institute -- Carr, Faustino, Nachman, Williams, Montalvo, Sheridan, Moquin, Bednarsky, Sandberg, Lippel, Johnson. Subs: Matygar, DeFaria, Kramcha, Radvany, Bowman, Lockhart.
Referee: Dave Jaworski.