Marco Mangione led the Blast with three goals and seven points.
After being held scoreless through the first quarter and much of the second, the Blast erupted for five goals in the final five minutes of the half for a 10-4 lead.
With the Blast trailing 2-0 on a goal by Rochester's Elliot Fauske, Mangione scored at the10:31 mark of the second quarter.
That goal was quickly followed by scores from Freddy Moojen, Lucas Roque, Pat Healey and Adauto Neto as the Blast took a 10-4 halftime lead.
Mangione added two more goals in the second half, including a 3-pointer.
The Blast got other second-half goals from Mike Deasel and Adriano Dos Santos.
Pat Healey led the Blast with two assists.
Andrew Hoxie scored two goals for the Lancers.
Blast goalie William Vanzela made 13 saves.
The Blast's home opener at Baltimore Arena will be Saturday at 7:35 p.m. against the Milwaukee Wave.