Wisconsin Sen. Ron Johnson won his rematch against Russ Feingold on Tuesday, aiding the Republican effort to retain control of the Senate.

The Johnson-Feingold race was a redo of the 2010 election when Johnson unseated Feingold, a Democrat. The only senator who has come back to win his old seat from the opponent who bested him was the late Sen. Peter Gerry, D-R.I., in 1934.

Feingold was initially thought to have a good shot to turn the tables on Johnson, but the race tightened significantly as the election came down to the wire.

A huge infusion of campaign committee and outside money poured into both sides of the race during the closing days. Johnson’s seat was thought to be vulnerable, and was one of several races Democrats targeted in an uphill battle to retake control of the Senate.

Republican presidential candidate Donald Trump, who was leading voting in the state late on Tuesday, put up far bigger margins than had been expected, perhaps helping to boost Johnson’s chances.

Feingold’s pitch for redemption centered on the claim that Johnson hadn’t done a strong job for Wisconsin voters during his six years in the Senate; however, Johnson argued the voters shouldn’t give Feingold a second shot at a job he’d already been sacked from once before.

Fox News’ Chad Pergram and The Associated Press contributed to this report.