Third-seeded Syracuse (10-2) will meet No. 2 Princeton (12-1) at Byrd Stadium on Saturday. The game is a rematch of last year's championship game, which Princeton won, 10-9, in double overtime.
Hofstra (10-6) ended a season in which it upset three top 10 teams and earned its first NCAA playoff victory.
Hofstra had hoped to control the tempo, but Syracuse attackmen Matt Riter (seven goals, two assists) scored five seconds into the game.
"We moved the ball around real well, and the big thing was we came up strong defensively, which led to a lot of good fast-break opportunities," Riter said. "I was on the very end of the fast breaks."
With its fast-break offense clicking, Syracuse built leads of 6-1 after the first quarter and 12-2 at the half.
"Maybe if it was 10-5, 10-6, our guys would have thought that it was a game, but at 10-2 [actually 12-2], it seemed like a mountain to climb," said Hofstra coach John Danowski.
Syracuse's defense stifled Hofstra, holding leading scorers Kevin Jacobs and Andy Carlson to one goal apiece. Dave Donatello, who scored eight goals against the University of Massachusetts during the regular season, was held scoreless.
"Our close defense kept their attackmen in check, especially Pat Cougevan with [Dave] Donatello," said senior defender Regy Thorpe. "That was a big boost for us. Ric [Beardsley] did a job on [Kevin] Jacobs and Chris [Surran] came up big in goal as usual."
Hofstra took 16 shots in the first half, but Surran made eight big saves. He had 13 for the game.
Hofstra 1 1 1 5 -- 8
Syracuse 6 6 3 5 -- 20