Broome County, New York, elected county officials on November 5, 2019, including a new District Attorney. The incumbent was not running for re-election. There were three candidates running. Two were seeking the Republican nomination, and one was seeking the Democratic nomination. Because New York allows fusion, all three also sought the Libertarian nomination.
The winner of the Republican primary was F. Paul Battisti. In that primary, Battisti defeated Michael Korchak, the chief assistant District Attorney. However, Korchak won the Libertarian nomination, and remained in the general election race, as the Libertarian nominee. He was not the nominee of any other party. Battisti was the nominee of the Republican Party only and was not the nominee of any other party.
The general election race was very close, and the winner was not known until November 19, when all the absentee votes had been counted. Korchak won the election. Here is a National Public Radio story about Korchak, an interview conducted before the election.
Here is a link to the election returns.