In a statement, Wagner congratulated Ball (R-Patterson) on the win and wished him well, accepting the re-elected senator's invitation over Twitter to "get together over a beer" and talk about the issues facing the Hudson Valley.
"I'm proud of the issues-based campaign that we ran, and I want to thank the voters for engaging in a lively discussion about the issues -- from raising the minimum wage, to standing up for reproductive health, to reforming our campaign finance system, to enacting common sense gun safety laws, to moving forward with substantive property tax relief," Wagner said in his statement.
"We fought for issues that impact middle class families in New York, and I will continue to do that as a private citizen," he added.
Ball could not immediately be reached for comment.
Ball has a nearly 4,000 vote lead over Wagner, according to an uncertified count of ballots cast in the Nov. 6 election, with about 6,800 absentee and a few thousand affidavit ballots uncounted. Wagner won the vote in Westchester, with Ball carrying Putnam and Dutchess.
Wagner's campaign said Ball's lead appears to be unsurmountable.
Ball, 35, declared victory this week, but Wagner's camp had refused to concede, arguing that the count of absentee and affidavit ballots could tip the outcome in his favor. Both sides called in lawyers to oversee the process.
Ball is a former state assemblyman who won his Senate seat two years ago by 2,000 votes. Wagner, 31, a Croton-on-Hudson attorney, was making his first run for office in the newly reconfigured 41st Senate District.
Democrats and Republicans are both claiming they've won control of the state Senate as weeks of counting paper ballots and likely legal challenges begin. Republicans held a 33-29 majority going into Tuesday's elections, but the Democrats had a strong showing on Election Day.
One Democrat from Brooklyn, Simcha Felder, who won his election, has said he will join the Republican caucus. Control of the state Senate will now likely hinge on a race for a new upstate seat created by the Republican majority. That race remains too close to call.