Newt Gingrich is peaking at the right time, according to a pair of primary day polls.

Both polls show the former House Speaker with at least a nine-point advantage over the rest of the Republican presidential field in South Carolina. 

One survey, conducted over the last three days before the pivotal GOP primary by Public Policy Polling, finds Gingrich the top choice of 37 percent of Republican voters.

Mitt Romney won 28 percent of those surveyed - around where he has consistently been polling in the Palmetto State for months. But Gingrich's late surge has the Romney campaign bracing for a South Carolina loss and an extension of the tough GOP primary.

Rick Santorum placed third in the PPP findings, earning 16 percent of South Carolina voters' support and narrowly edging Ron Paul, who got the nod from 14 percent of those surveyed.

Another one, by American Research Group, found Gingrich with 40 percent support of South Carolina Republican voters, with Mitt Romney in second with 26 percent and Ron Paul in third with 18 percent. That's Gingrich's best showing since early December of last year, just before super-PACs supporting Mitt Romney and Ron Paul began airing a series of devastating attack ads questioning the former Speaker's past baggage.

At a campaign stop on the U.S.S. Yorktown Friday night, Gingrich urged supporters to help him convert his lead in the polls to victory.

"I have to appeal to you … to vote, because the polls don't count if you don't vote," Gingrich said. "I do not believe we can defeat Barack ObamaBarack Hussein ObamaFeehery: Betting on Trump Pew study finds Americans can’t tell fact from opinion Should President Trump, like President Obama, forsake human rights in pursuit of the deal with a tyrant? MORE with a Massachusetts moderate."

Still, victory is not assured. The Romney campaign's better finances and organization traditionally translate to better get-out-the-vote efforts, and forecasted thunderstorms in the central and northern areas of the state could keep turnout low.

This post was orginally posted at 10:05 a.m. and has been updated.