Control of the US Senate will not be decided until the new year after Republicans won a seat in Alaska.
Neither the Republicans or Democrats can assume a majority until January run-off elections in Georgia.
Incumbent Alaska Republican senator Dan Sullivan defeated Al Gross, an independent running as a Democrat, on Wednesday.
With Democratic president-elect Joe Biden’s victory, Republicans are still short of the 51 seats they need for majority control. They have a 49-48 hold on the Senate with the Alaska win, but two races in Georgia are heading to a run-off on January 5.
The race in North Carolina remains too early to call, where Democratic challenger Cal Cunningham has conceded to Republican senator Thom Tillis.
With Mr Biden as president-elect, the path to keeping Senate control is more difficult for Republicans. The vice president of the party in power, which on January 20 will be Kamala Harris, is the tie-breaker. That means if Republicans only have 50 seats, Democrats control the Senate.
The Georgia run-off elections are swiftly becoming a showdown over control of the chamber. The state is closely divided, with Democrats making gains on Republicans, but no Democrat has been elected senator in some 20 years.
Republican senator Kelly Loeffler will face Rafael Warnock, a black pastor from the church where Martin Luther King Jr preached, while Republican senator David Perdue, a top Trump ally, will face Democratic challenger Jon Ossoff.
