Andrews, a 50-year-old lawmaker who has served in the House since 1990, recalled in one television ad how Lautenberg himself raised the age issue when campaigning in 1982 against Rep. Millicent Fenwick, who was 72.
"It's hard when your own words come back to haunt you, isn't it?" the ad asked.
Lautenberg, 84, insisted he was criticizing Fenwick's age relative to her political experience.
He will face former Congressman Dick Zimmer, who won New Jersey's Republican U.S. Senate nomination.
Zimmer bested state Sen. Joseph Pennacchio and college professor Murray Sabrin in Tuesday's primary.
The 63-year-old Zimmer has been out of elected politics for a dozen years after losing the 1996 U.S. Senate race and a 2000 House race. He has been a Washington lawyer and lobbyist.
Here is an overview of U.S. House primaries in New Jersey Tuesday.
There were also contested primaries in seven House districts in New Jersey, including three where the sitting congressmen are not seeking re-election:
Only two House incumbents faced challenges, but Republican Frank LoBiondo in the 2nd District and Republican Rodney Frelinghuysen in the 11th District were easily nominated for re-election.
On the Net:
New Jersey Division of Elections: http://www.njelections.org/