Eighteen percent of likely voters support Kashkari and 13 percent support Donnelly, with 10 percent undecided, according to the poll.
Both Republicans remain far behind Gov. Jerry Brown. The Democratic incumbent registered 50 percent support among likely voters. The race between Kashkari and Donnelly is to determine who will advance to a runoff against Brown in the fall.
The difference between Kashkari and Donnelly is within the poll's margin of error. But it represents a major improvement for Kashkari, who consistently trailed Donnelly in public opinion polls all year. The poll released Sunday follows an advertising push by Kashkari in the final weeks of the campaign.
PHOTO: PHOTO: Republican Neel Kashkari speaks with reporters at Oroville Dam on March 28, 2014. The Sacramento Bee/David Siders