Rep. Jeff Flake, R-Ariz., made the jump to the Senate after six terms in the House by defeating former U.S. Surgeon General Richard Carmona in the race for the seat Kyl is retiring from.
Flake was projected as the winner by CNN with 65 percent of the votes counted. He had 51 percent of the vote compared with 45 percent for Carmona.
Three of the nine House races in Arizona remained up for grabs as the final votes were tallied Tuesday.
Districts 1, 2 and 9 were too close to call with more than 85 percent of the votes counted.
Democrat Raul Grijalva was declared the winner in District 3 and Ed Pastor won in District 7.
Joe Arpaio, the high-profile veteran sheriff of Maricopa County, was elected to a sixth term. Arpaio has been a controversial figure in Arizona because of his hard line on the treatment of jail inmates and long-running allegations of discrimination against Hispanics.