Both Oceguera and Heck won their respective primaries against a handful of little-known candidates Tuesday.
Oceguera bested five Democrats to earn his slot in the November general election, while Heck easily fended off one Republican rival.
Oceguera and Heck were expected to win their primary contests and the two have been sparring for months over who is best equipped to put Nevada's troubled economy back on track.
The 3rd District contest is expected to be among the closest races in the state because the district that includes Henderson is evenly divided between Democrats and Republicans.
Heck was elected to the House in 2010 after defeating Democrat Dina Titus.