Ultimately, Shuster edged out his opponent 50.52% to 49.48%. The difference was just 1,009 (48,686 to 47,677) with 99% of precincts in.
This is the second straight victory for Shuster over Halvorson.
The House Transportation Committee Chairman will now run unopposed in the November general election.
The 9th Congressional District consists of all or parts of Bedford, Blair, Cambria, Fayette, Franklin, Fulton, Greene, Huntingdon, Indiana, Somerset, Washington and Westmoreland Counties.