Jon Ossoff and Raphael Warnock are hoping to win for the Democratic Party while Kelly Loeffler and David Perdue want to keep their seats for the Republican side.
Both sides are taking starkly different approaches in an unusual race which has become the epicentre of a national battle for control of the Senate.
Both sides are playing to core supporters, the most reliable voters among the 5 million who split their ballots roughly evenly between the two parties in the first round.
But for Democrats, it’s seemingly a more piecemeal, voter-by-voter approach, while Republicans are pushing a broad branding message through mass media.
Whichever strategy proves more effective on January 5 will help determine the ambitions and reach of President-elect Joe Biden’s tenure depending on which party ultimate controls the chamber.
Republicans need one of the Georgia seats for a majority.
Democrats must win both to yield a 50-50 Senate, with Vice President-elect Kamala Harris then holding the tie-breaking vote.