Sen. Susan Collins has opened a small lead over Democratic challenger Troy Jackson in Maine's closely watched Senate race, according to a New York Times/Siena poll released Thursday.

The survey of 619 likely voters, conducted Sept. 15-22, found Collins with 49% support compared with 46% for Jackson, while 5% remained undecided. Collins' three-point advantage is within the poll's 4.9-point margin of error, leaving the contest statistically close.

The result represents a shift from some earlier polling and is the first major public survey since Jackson became the Democratic nominee to show Collins ahead. Collins had trailed Jackson's predecessor, Graham Platner, in a June Times/Siena survey before Platner's withdrawal from the race.

Jackson entered the contest after Platner withdrew following numerous allegations, including an alleged sexual assault. Platner refuted all allegations as "troubling, serious" and "categorically false" and announced his resignation from the race in July. Jackson, a former president of the Maine Senate, has campaigned on progressive proposals including Medicare for All, abolishing Immigration and Customs Enforcement and raising taxes on billionaires and corporations.

Collins' personal standing in the poll differs from the broader political environment in Maine. Fifty-one percent of respondents viewed the Republican senator favorably, compared with 48% who viewed her unfavorably. Jackson registered 41% favorable and 49% unfavorable ratings.

The survey also found that 55% of respondents preferred Democrats to control the Senate next year, compared with 43% who wanted Republicans to retain the chamber. Collins nevertheless held a three-point advantage in her individual race.

Collins has sought to maintain a distinct political profile in a state that has not always aligned with the national Republican Party. She has criticized President Donald Trump's tariffs on Canada and opposed the confirmation of Attorney General Todd Blanche. She has also worked with independent Sen. Angus King on legislation concerning Maine's lobster industry.

The race has attracted substantial national attention because Democrats are targeting Collins' seat as they seek to regain control of the Senate. Republicans currently hold a 53-47 majority, meaning Democrats would need a net gain of four seats to take control.

The latest survey was conducted before a recent ProPublica report concerning a previously dropped federal corruption investigation involving Collins. Collins has denied the allegations described in the report. The timing limits what the poll can show about whether the controversy has affected voters.

With 5% of voters undecided and Collins' lead falling inside the survey's margin of error, the poll shows a closely contested race heading into the final weeks of the campaign.