As results came in Tuesday night, both candidates gathered with friends and family at St. Louis area watch parties.
Initially, it was a tight race, but ultimately Zweifel declared victory and thanked his supporters just before midnight.
"I think a lot of this illustrates hard work and investment in each other," Zweifel said.
With 100 percent of the precincts counted early Wednesday morning, Zweifel had 50.3 percent of the vote and McNary had 45.5 percent of the vote.
Zweifel tells Patch McNary did call him and concede Tuesday night.
Both parties tell Patch they knew it would be a close race.
"It's a competitive race," McNary tells Patch.
Zweifel, who now lives in Columbia, MO, was elected in 2008 after six years as a state representative from Florissant. Sworn in as Missouri’s 45th treasurer at the age of 35, Zweifel's staff said he became Missouri’s youngest state treasurer in more than a century.
According to the St. Louis Post Dispatch, Zweifel, 39, said he deserves a second term based on his record during his last four years in the job. In a recent article, Zweifel cited expanding Missouri's small-business loan program, managing the state’s investments to help retain Missouri’s triple-A credit rating and getting a rating of excellent from the state auditor, a Republican, as reasons he should remain in the position.
He has repeatedly said during campaigning that protecting Missouri's AAA credit rating is a top priority and reiterated its importance Tuesday night.
In the next four years Zweifel tells Patch he plans to continue investing in small business and improving the Missouri entrepreneurial environment, including connecting small businesses with community lenders.
"First to maintain our strong place in terms of fiscal responsibility. That's critical for out state to move forward. That challenge doesn't rest," Zweifel said. "Second, making smart investments in Missouri small businesses and entrepreneurs to help them create jobs."
McNary, 48, a state representative from Chesterfield, was elected in 2008 and represents District 86 which is Chesterfield in West St. Louis County.
McNary's original district seat no longer exists due to redistricting and the majority of what was his district will now be represented by state representatives John Diehl and Sue Allen.
McNary tells Patch that as treasurer, he had planned to address pension health overall and “underfunded" public pension systems across Missouri as state treasurer.
"I would say the pensions issue is really dynamite. It's a ticking time bomb," McNary tells Patch. My guess is that it won't get done. My guess is that it wil be pushed into the future for somebody else to deal with. But we could be surprised. We raised the issue."
McNary said his desire to run for state treasurer stemmed from when he initially ran for his current state representative position.
"When I was first running for office and was knocking on doors, the general message people gave me was that government was out of control," so as a state representative, McNary said he focused on downsizing state government and restructuring it to become more responsive and more efficient. "It was mainly centered on 'What can we get rid of?' The interest in running for treasurer was a continuation of that work."
McNary said since he did not win the race for state treasurer, he plans to go back the private sector when his term is up in January. He is not sure specifically what he will focus on.
"I did a lot of things over my career. You know, the world is a changing all the time, getting better all the time," McNary tells Patch.
Zweifel will be sworn in for his second term this January.
The state treasurer can serve only two consecutive four-year terms. His or her annual salary is reportedly $107,746.