Kelly, a former NASA astronaut whose former-Congresswoman wife Gabrielle Giffords was shot in the head and survived, defeated Republican venture capitalist Blake Masters.
The news now puts his party one victory away from clinching control of the chamber for the next two years of Joe Biden’s presidency.
Republicans now must win both those races to take the majority.
Mark Kelly has been re-elected to the Senate, representing Arizona. His win means that the Democrats are only one victory away – either Nevada or Georgia – from clinching control of the Senate for the rest of Joe Biden’s term
Kelly defeated the Trump-backed Republican venture capitalist Blake Masters
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.
Other Arizona contests, including the closely watched race for governor between Democrat Katie Hobbs and Republican Kari Lake, were too early to call Friday night.
Kelly, who has flown in space four times, is married 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.
Kelly’s victory in a 2020 special election spurred by the death of Republican Sen. John McCain gave Democrats both of Arizona’s Senate seats for the first time in 70 years.
The shift was propelled by the state’s fast-changing demographics and the unpopularity of Trump.