Rep. Tom Malinowski (D-Ringoes) now leads by 4,327 after Republican Thomas Kean, Jr. (R-Westfield) picked up 277 more votes in Union County on Friday.
The freshman Democratic congressman now leads Kean, the minority leader of the New Jersey State Senate, 208,585 to 204,258, 50.5% to 49,5%.
Union County added 3,807 votes to their 7th district tally, with Kean getting 53.6% of those votes.
Malinowski started the day with a 5,496-vote lead over Kean. The freshman congressman was in front of Kean by 28,412 votes on election night.
Kean picked up 551 votes in Morris and 341 in Somerset on Friday.
Malinowski, a former Assistant U.S. Secretary of State in the Obama administration, unseated five-term Rep. Leonard Lance (R-Clinton Township) in 2018 by 16,200 votes, 51.7% to 46.7%.
He was the first Democrat to win the 7th since 1956.
Kean, the son of former Gov. Thomas H. Kean, has served in the New Jersey Legislature since 2001.