The Senate contest was the marquee race in an election where Republicans appeared poised to sweep most if not all other statewide seats.
Democrat Kyrsten Sinema and Republican Martha McSally tie at 46 percent apiece among Arizona likely voters.
The hotly contested Arizona Senate race between Republican Martha McSally and Democrat Kyrsten Sinema will come down to election day turnout, according to a new poll released late Sunday by OH Predictive Insights and ABC15.
An official victor may not be known for days - and maybe longer if the final tally triggers a recount or legal challenge, experts said.
That leaves the contentious Senate race a cliffhanger in what's otherwise shaping up to be another banner Arizona year for Republicans. Ducey is facing Democrat David Garcia, an education professor.
The avid triathletes are battling over the seat vacated by Sen.
Term election results: What it all means for Trump
The Republican president is the omnipresent figure as Americans render their verdict Tuesday on the past 21 months of Trumpism. About two in 10 each choose the economy and immigration as their top issue, and just one in 10 say it's gun policy.
New world number one Novak Djokovic sets personal record at Paris Masters
But when the new rankings are released on Monday, it will be Djokovic's name at the top for the first time since October 2016. Khachanov, who won the Kremlin Cup in Moscow last month, did not face a break point in the 2 1/2-hour match.
Trump speaks by phone with China's Xi on trade
At a campaign rally in Columbia, Missouri, he later said "they want to make a deal". "It looks like they are focusing on trade". Neither leader specified any details of potential progress in their first known direct discussion in several months.
McSally has painted Sinema as a radical leftist based on her activism in Green Party circles during the early 2000s, deploying old clips and images to tarnish Sinema, such as a photo of Sinema wearing a pink tutu at an anti-war protest. All three are running to replace retiring Senator Jeff Flake. "OHPI found that 88 percent of Sinema's voters have already turned in their ballots, while only 70 percent of McSally's voters have done the same".
McSally and Sinema have both remade themselves politically. McSally, 52, is a onetime Trump critic who has embraced the president since his election.
No matter who wins, Arizona will see the first female USA senator in state history. The repeal of the Affordable Care Act, which didn't become law, would have weakened protections for people with pre-existing conditions. More Arizona voters identify as Republican than as Democrat by 10 points. She remained optimistic about a Sinema victory.
Sinema faced no real opposition in the Democratic primary and had months to define herself as a nonpartisan, problem-solving centrist on the airwaves while her allies slammed McSally with attack ads over the Republican's health care vote.
Flake won his U.S. Senate election in 2012 by 3.5 percentage points. Also at stake is Arizona's role in national elections.
If she wins, her campaign could become a centrist blueprint for Democrats eager to win in deep-red Republican strongholds.