Former Pennsylvania Senator Rick Santorum has won the Republican primaries in Minnesota, Missouri and Colorado, handing a major defeat to former Massachusetts governor Mitt Romney.

Santorum had campaigned hard in Minnesota and Missouri in an effort to win the support of Tea Party backers and Evangelical Christian voters.

With 99 percent of votes counted in Missouri, Santorum leads with 55 percent, followed by Romney with 25 percent and libertarian Congressman Ron Paul with 12 percent, CNN reported. Another candidate, former House Speaker Newt Gingrich, did not make the ballot in Missouri.

With 88 percent of the votes counted in Minnesota, Santorum leads with 45 percent followed by Paul with 27 percent, Romney with 17 percent and Gingrich with 11 percent.

In Colorado, with 99 percent of the vote counted, Santorum's lead has widened to 40 percent of the votes to Romney's 35 percent.

The Republican field has been whittled down to four candidates since primary voting began in January. Republicans will formally nominate their candidate for the presidency at the party convention in September.