(CNN) With three weeks to go before the Iowa caucuses, it's a two-man race between Ted Cruz and Donald Trump.
A new Bloomberg/Des Moines Register poll released Wednesday shows that Texas Sen. Cruz is on top in the first primary contest state with 25% support, ahead of Trump with 22%, though that's within the poll's 4.4 percentage point margin of error.
Florida Sen. Marco Rubio and Ben Carson appear locked in a battle for third place, with Rubio finishing third in the poll with 12% support, just in front of Carson in fourth with 11%.
Beyond those top tiers, no other candidate registers more than 5% support.
Rand Paul, who was eliminated from the main debate stage for Thursday's Fox Business debate because of his low polling, placed fifth in the poll with 5%, followed by Jeb Bush with 4%, and Chris Christie and Mike Huckabee with 3%.
Carly Fiorina and John Kasich both polled at 2% support, while Rick Santorum, the winner of the 2012 Iowa caucuses, received just 1%.
The Bloomberg/DMR survey also questioned respondents about their second choice candidates, which revealed that Cruz's position in Iowa is particularly strong. He is the "second choice" candidate of 23% of likely Republican caucus-goers, according to the poll, while Rubio is the second most popular alternative option, with 16% saying he is their second choice.
Trump's "second choice" support is 11%, ahead of Carson at 8%. The rest of the GOP field is clustered between 2-4% support as a second option, indicating that with weeks to go before voting, Iowa Republicans have entered a critical decision-making phase.
The poll was conducted among 500 likely Republican caucus-goers between January 7 and January 10.