Ziegler hammered Murphy for supporting cap-and-trade air pollution abatement policy, which he argued is driving jobs to China and Russia.
Ziegler said he was shocked by the outcome, especially the fact he beat Stec in his hometown.
"We are very confident in the people we have behind us and our platform in this election cycle," Ziegler said. "I was very surprised we won in Warren because Dan Stec is an excellent candidate and a real good guy."
The remaining nine G.O.P committees in the district are expected to make their endorsements over the next several weeks.
A call to Stec's office wasn't answered by Tuesday noon, but area news media reported that Stec plans on remaining in the race, even after losing his home county.
New York's 20th Congressional District stretches from Essex County south to Dutchess County.