Matheson won by a 108,075 to 105,257 vote margin, a difference of 2,818 votes.
Both candidates have been locked in a heated battle over the past 5 months, with campaign money pouring in from out-of-state sources, including super-PACs that funded several negative TV ads.
Matheson chose to run in the new congressional district instead of seeking reelection in the 2nd District, where he has served as U.S. Representative since 2001.
Early Wednesday morning, Saratoga Springs Mayor Mia Love issued a statement congratulating Matheson, saying:
“Congratulations to Jim on a hard fought victory,” said Love. “It was a close race, but ultimately the voters of Utah have spoken. I want to thank the hundreds of volunteers and staff who worked tirelessly for my campaign, and am humbled by their dedication and commitment to the betterment of Utah and our nation. I plan on continuing to work on promoting conservative issues and look forward to returning to Saratoga Springs and spending more time with my family.”
The Associated Press refused to call the race for Matheson, citing the need to count provisional ballots that might swing the official result.
The electionresults.utah.gov website includes a disclaimer for that says all its election night results are are "preliminary" and are posted on the web as a convenience to the public.
The disclaimer outlines other steps involved in counting and auditing election results, which need to be checked for accuracy and completeness before they are made final.