With just 12 days to go before the mayoral runoff, a poll released Thursday finds Wendy Greuel leading Eric Garcetti by one point — a statistical dead heat.

The survey from the Pat Brown Institute at Cal State L.A. is the latest sign of how unpredictable the race has become. Greuel leads with 46 percent, with Garcetti at 45 percent. Nine percent of voters were undecided.

The numbers are in dramatic contrast to a USC/L.A. Times poll released on April 20th that showed Garcetti with a 10-point lead.

Raphael Sonenshein, executive director of the Pat Brown Institute, cautioned that comparing polls is like comparing apples and oranges, as each survey has its own makeup of participants. As for why there may have been such a shift in support in the past three weeks,  he said: "It could be that more people are tuning into the race who weren’t tuned in before."

He added: “It’s possible that some of the messages are making a difference because the candidates aren’t yet all that well defined." During the time the poll was conducted, the Working Californians PAC began airing a TV ad touting former president Bill Clinton's support for Greuel.

Ultimately in such a low turnout race, small shifts in a candidate's base can make a huge difference.

“It’s not the overall turnout that matters – it’s who turns out," Sonenshein said. 

 Turnout in the March 5 primary was just 21 percent.

According to the poll, Greuel is leading among African-American and white voters. She is also 11 points ahead with women voters. Garcetti leads among Latino and Asian-American voters.

Regardless of their own preference, half of the voters surveyed said they believe Garcetti will win. Participants said he would do a better job leading the city and fighting crime, while Greuel would do better with schools. She was also seen as a candidate who “cares about people like me.”

The results are based on phone surveys with 674 likely voters between April 29 and May 7.  There is a margin of error of four points.

The runoff is on May 21.