HARTFORD, Conn. (AP) -- Greenwich businessman Tom Foley on Tuesday won the Republican primary for governor, setting up a rematch with Democrat Dannel P. Malloy, who narrowly defeated him four years ago.

Foley, a former U.S. ambassador to Ireland under President George W. Bush, defeated Senate Minority Leader McKinney, a 16-year veteran of the General Assembly from Fairfield, according to unofficial returns late Tuesday.

Even during the primary campaign, Foley focused heavily on the record of Malloy, who defeated Foley by just 6,404 votes out of 1.1 million votes cast in 2010 to win his first term as governor.

Foley has criticized Malloy for agreeing in 2011 to raise taxes by $2.6 billion over two years to help cover a projected $3.3 billion budget deficit he inherited and promoting what Foley considers to be anti-business policies, such as mandatory paid sick leave. Foley has dismissed various tax credit, grant and loan programs for employers as "giveaways" and "corporate welfare."

Foley received the state GOP's endorsement at a convention in May and was considered the favorite. He has never held elected office but argues his business experience makes him the best candidate to run state government efficiently and attract investment to the state.

The wide-ranging Connecticut gun control law passed after the December 2012 school shootings in Newtown figured prominently in the primary campaign. McKinney, whose district includes Newtown, where a gunman killed 20 children and six adults at Sandy Hook Elementary School, has defended his work to help craft the bipartisan legislation. Foley has avoided outlining specific concerns with the law but says he disapproves of restrictions on law-abiding gun owners.

Foley said at a debate last weekend that he would support the Democrat-controlled General Assembly if it decided to revisit the law but would not initiate such legislation given the makeup of the legislature.

Foley cast McKinney as a political insider and career politician.

"I represent a change in direction," Foley said at a debate last weekend. "I'm not a career politician. I'm not an insider. I'm not part of the problem."

McKinney accused Foley of being short on specifics when it came to his public policy proposals.

McKinney, the son of the late U.S. Rep. Stewart McKinney, a Fairfield County Republican, proposed eliminating state income taxes on those who make less than $75,000 a year, saying middle-income earners have been hurt the most by Malloy's policies.

Foley has called for a 0.5 percent reduction in the state's 6.35 percent sales tax and a review of the state's tax structure.

Foley, after spending more than $10 million of his own money on the 2010 race, announced in June that he would use Connecticut's public financing program to fund this campaign. He said his decision was prompted by changes in state election laws, such as new restrictions on donors.

Since the 2010 race, Foley and his wife have become parents to twins, who are now 2 years old. Foley also has a son from a previous marriage.