A House of Representatives district in Massachusetts may have had one of the closest contests in recent election history.

CBS News reports that Democrat Kristin Kassner has taken a one-vote lead against incumbent Republican Rep. Lenny Mirra after an election recount was completed on Thursday.

Politico reports that 23,525 votes were cast in the Massachusetts 2nd Essex District state house election.

Kassner now has 11,763 votes, compared to Mirra’s 11,763.

Kassner was able to request a recount because the incumbent Republican initially led by a margin of 10 votes after the election, which was narrow enough to warrant a recount.

A last set of votes from the village of Topsfield changed the election’s outcome in the recount, with the five-term Republican incumbent surrendering the lead to his opponent, according to CBS.

Mirra intends to litigate voting procedures, citing a handful of spoiled ballots that might eventually tilt the election in his favor.

“It’ll absolutely be a legal challenge,” Mirra said of his plans to formally fight the election, pointing to multiple claimed improprieties that might potentially alter the conclusion of a campaign determined by a single vote.

“Yesterday, in Rowley, they were able to use five spoiled ballots that all went to my opponent,” the incumbent said of the recount. “In no other town did they let us use spoiled ballots.”

Mirra fears that a number of absentee ballots were counted despite envelope signatures that did not match the intended voter.

The Republican argues a state legislative redistricting procedure left him susceptible in the election, which went poorly for Massachusetts Republicans.

“I got totally screwed in this redistricting. I lost five of my seven towns.”

“Usually, a rep district changes by maybe five percent or 10 percent,” Mirra said of his new district. “It’s an unheard-of amount of change for my district.”

Democrats extended their majority in the Massachusetts House of Representatives and elected a Democrat to succeed outgoing Republican Governor Charlie Baker.

Another tightly contested race for the Massachusetts House is likely to wind up in court.

Politico reports that Democrat Margaret Scarsdale leads Republican Andrew Shepherd in the 1st Middlesex District by 11 votes.

The current recount has reduced Scarsdale’s advantage from 17 points to 2.