Republican presidential candidate Donald Trump arrives on stage for a campaign event at Clinton Middle School on January 30, 2016 in Clinton, Iowa. (Photo by Joe Raedle/Getty Images)

URBANDALE, Iowa -- The most respected poll in Iowa showed Donald Trump leading Sen. Ted Cruz (R-Tex.) in the Republican race here 48 hours before the first-in-the-nation presidential caucuses, with Sen. Marco Rubio (R-Fla.) running third.

Trump leads the way with 28 percent among likely Republican caucus-goers, according to the Des Moines Register/Bloomberg Politics survey released Saturday. Cruz clocks in at 23 percent while Rubio is at 15 percent.

Ben Carson is fourth with 10 percent. The rest of the field registered single-digit support.

Trump's support has climbed from 22 percent in the previous poll in early January. Cruz is down slightly from 25 percent. Rubio is up a tad from 12 percent.

While Cruz once looked poised for a win in Iowa, he has faced heavy criticism from Trump and Rubio in recent weeks. Cruz has hit back against Trump and appeared increasingly worried about Rubio this week; he started running an attack ad calling Rubio the "Republican Obama."

When asked about Saturday's poll, Cruz said he feels good about where he is in what he called “effectively a two-man race.”

“I am thrilled where we are right now,” he told reporters in Sioux City, Iowa. “If you had told me a year ago that two days out from the Iowa caucuses we would be neck and neck, effectively tied for first place in the state of Iowa, I would have been thrilled.”

Republican presidential candidate Marco Rubio took aim at rival Ted Cruz on CBS's "Face the Nation," saying Cruz is "not what he portrays himself to be." (Reuters)

Katie Zezima in Sioux City, Iowa contributed to this post