Mark Rozzi defeated two other candidates to win the Democratic bid for the Pa 126th District.
In January, incumbent Dante Santoni decided not to seek an 11th term in the state House of Representatives.
Rozzi, 40, of Muhlenberg Twp., Berks Co., defeated two challengers and will face Republican James Billman, 48, also of Muhlenberg Twp. in the Nov. 6 general election.
Billman ran unopposed for the Republican nomination in the primary.
The 126th District is made up of Laureldale, Mount Penn and St. Lawrence boroughs and Alsace, Lower Alsace and Muhlenberg townships. It also includes parts of Reading and Exeter Township.
PA House of Representatives, 126th District (D)
Mark Rozzi 2,735 59%
Frank Denbowski 1,535 33%
John Delcollo 352 8%
Allentown, PA 18102