The former Lackawanna County prosecutor defeated former U.S. Rep. Patrick Murphy, 53 percent to 47 percent with nearly 90 percent of the vote in Tuesday's primary counted.
The two candidates waged a spirited campaign that was heavy on TV advertising.
The 45-year-old Kane touted her nearly 13 years' experience as a prosecutor while reminding voters that Murphy has never tried a case in Pennsylvania courts.
The 38-year-old Murphy stressed his five years in the U.S. Army Judge Advocate General Corps and asserted that he was the true Democrat in the race.
Kane relied heavily on her family's wealth to finance her campaign, while Murphy received help from major labor unions.
