Incumbent state Sen. Luther Olsen overcame a challenge from Democrat Fred Clark to prevail in a recall election, with Clark conceding late Tuesday evening.
Unofficial results showed Olsen getting 54 percent of the vote to Clark's 46 percent, according to The Associated Press.
Olsen was among three of six Republican incumbents to hold off challenges. Three other recall races remained too close to call.
Olsen's victory is a huge win for Republicans as they attempt to maintain majority control of the Senate.
Olsen has been elected twice before to the Senate, but he ran unopposed both times. The race attracted huge amounts of outside money spent primarily on television ads in the Madison and Green Bay markets.
With 120 of 126 precincts - or 95 percent - the AP had Olsen leading Clark 23,868 votes to 19,995.
Olsen addressed a crowd at the Royal Ridges Conference Center in Ripon just minutes after he was declared the winner. He slowly made his way through the room, shaking hands and hugging supporters.
"Well, we did it," Olsen shouted as he took the podium to a round of applause.
Throughout the race, he said, critics of the policies enacted by Republicans in recent months told him he wasn't listening to his constituents.
"Tonight, my constituents spoke," he said, adding that those policies seem to be working. "We did what the folks in the 14th Senate District wanted us to do."
Olsen thanked his staff, wife and family, as well as his supporters. He said Tuesday's results show that when politicians balance a budget without raising taxes, they win constituents' support.
Constituents upset with Olsen's support for Gov. Scott Walker's controversial collective bargaining bill were what sparked the recall election, which gave Olsen his first Democratic challenger in 16 1/2 years in office.
But union workers and their benefits weren't what motivated Tim Holz, of Ripon, who attended Olsen's election night gathering, to vote for the Republican senator Tuesday.
"Even though this election is about collective bargaining, I'm a social conservative," Holz said, adding that it is Olsen's position on issues like abortion that got him to the polls.
Democrats need to flip three seats to take control of the Senate. Holz said if Democrats can't do that, he doesn't believe it's likely they will try to recall Walker.
G.R. Cady, a retired firefighter from Oshkosh who attended Olsen's gathering, said he has seen a decrease in his monthly pension as a result of the collective bargaining bill Olsen supported. It doesn't bother him.
"If it's good for the country, then so be it," he said. "They can take more."
Cady said he was happy to make the sacrifice and the state needed to get its fiscal house in order.
"I'm looking out for my grandkids and my great grandkids," he said.
At the Best Western in Portage, a different scene was playing out. Clark appeared before the crowd and conceded the election after 10 p.m.
A short time earlier, Roger Springman of Wyocena said he has seen a large chunk of the sprawling 14th Senate District - encompassing parts of 10 counties - as he campaigned for Clark in the past few months. On Tuesday, he said, he canvassed in Berlin and carried a pro-Clark sign in Portage.
"Carrying signs - that's one of my specialties," he said.
As Springman spoke about 9 p.m. Tuesday, Clark was trailing Olsen. With 40 percent of the 14th District's precincts reporting, Olsen had about 55 percent of the vote to 45 for Clark.
Even with a Clark loss, Springman said, the efforts to recall Olsen were well worthwhile.
"This is a push-up effort for democracy, and the Constitution allows it," Springman said. "People are glad they did this, and it was all worth it."
Arlene Kanno of Wisconsin Dells said she was "making my contributions in my own way" to Clark's campaign by working in Baraboo on Tuesday to help get out the vote.
Kanno said the election - even if it were to result in a Clark loss - was worthwhile because it called voters' attention to the power that corporations are exercising in Wisconsin politics.
"This means the little guy - even though each of us theoretically has one vote - is down the drain," Kanno said.
Sarah Lloyd, a rural Wisconsin Dells dairy farmer, agreed. The "large corporate lobby" put Walker in power and Republican lawmakers in power, she said, and "We need to educate voters about what's really going on here."
Sauk County favored Clark over Olsen, with the Baraboo Democrat getting 4,210 votes to the Ripon Republican's 2,833 according to the Sauk County Clerk's Office.
In Columbia County voting, Clark was leading Olsen 2,444 to 1,897. That tally didn't include the city of Portage, or the other eight counties that are part of the district.
Turnout varied by location, but was about double the 20-25 percent turnout during the primary, in line with what Columbia County Clerk Sue Moll said her office predicted.
"We've just established a baseline for recall elections, I guess is what I can say," Moll said at about 8:40 p.m.
By that point, her office had received ballots for all precints except Portage and Lewiston.
Moll said she understood there were long lines at the Portage voting location; as long as a person made it into line by 8 p.m., Moll said, that person would be able to vote. The last vote was cast at 8:40.
The 14th Senate District boundaries stretch from Waupaca County in the north to northwestern Columbia County and northeastern Sauk County to the south. In between, it includes all or part of Outagamie, Waushara, Fond du Lac, Green Lake, Marquette and Adams counties.
The Associated Press contributed to this report.