Out of 16,892 votes cast, Bachmann took 4,823, just ahead of Paul's 4,671. Pawlenty who essentially staked his campaign on the straw poll, got just 2,293 votes, less than half of his fellow Minnesota lawmaker. Bachmann became the first woman to win the event, the LA Times reported.
But Bachmann has the advantage of being born in Iowa and has been a fixture in the state since announcing her campaign in Waterloo, the city of her birth, USA Today reported.
Since late June, she has visited the state 34 times and held 67 events, according to the tally on the Des Moines Register's website.
The win comes after a tense debate between her and rival Pawlenty, who had repeatedly described her record as "non-existent."
Bachmann had also invested heavily at the straw poll, the New York Times reported. She bused supporters there, and held them in an air-conditioned tent with free barbecue and promised live music from Randy Travis.
Winning the straw poll doesn’t guarantee a victory in the more important Iowa caucuses. Mitt Romney won the poll in 2007 and then lost to Mike Huckabee when it counted five months later. And Perry’s candidacy announcement today unsettles the race for Republican candidates.