Democratic Sen. Mark Kelly won his bid for reelection Friday in the crucial swing state of Arizona, defeating Republican venture capitalist Blake Masters to put his party one victory away from clinching control of the chamber for the next two years of Joe Biden’s presidency.

With Vice President Kamala Harris’ tiebreaking vote, Democrats can retain control of the Senate by winning either the Nevada race, which remains too early to call, or next month’s runoff in Georgia. Republicans now must win both those races to take the majority.

The Arizona race is one of a handful of contests that Republicans targeted in their bid to take control of the 50-50 Senate. It was a test of the inroads that Kelly and other Democrats have made in a state once reliably dominated by the GOP. Kelly’s victory suggests Democratic success in Arizona was not an aberration during Donald Trump’s presidency.

The closely watched race for governor between Democrat Katie Hobbs and Republican Kari Lake was too early to call Friday night. In the secretary of state’s race, Democrat Adrian Fontes defeated Republican Mark Finchem, a top 2020 election denier.

Kelly, a former NASA astronaut who’s flown in space four times, is married to former U.S. Rep. Gabby Giffords, who inspired the nation with her recovery from a gunshot wound to the head during an assassination attempt in 2011 that killed six people and injured 13. Kelly and Giffords went on to co-found a gun safety advocacy group.