The predictable victories Tuesday night ensure the two will remain locked in what already has been a nasty election battle that could decide whether Democrats retain control of the U.S. Senate.
Early voter returns show Heller besting four other Republicans, while Berkley was trumping four rivals.
Heller was appointed to the Senate last year after Republican John Ensign resigned. Heller served as Nevada's secretary of state before being elected to the U.S. House to represent northern Nevada in 2006.
Berkley was first elected to represent Las Vegas in 1998.
The general election will likely be a close match.