PHOENIX (AP) -- Rep. Russell Pearce won the Republican nomination for an open Senate seat in a race that saw foes pour money and mud into their efforts to oust the Arizona Legislature's most ardent foe of illegal immigration.

But several other prominent lawmakers were losers in other primary races Tuesday. They included the third-ranking House Republican, a GOP senator who regularly bucked his party on fiscal and other issues and a representative with a recent drunken-driving conviction.

Pearce defeated immigration attorney Kevin Gibbons, 5,717 votes, or 69 percent, to 2,587 votes, or 31 percent, with all 51 precincts reporting in results from the Republican primary for the Senate seat from Legislative District 18 in Mesa, a Phoenix suburb.

Pearce drew opposition from business interests for his stance on the immigration issue as farmers and others poured money into the race. In turn, Republican Party activists rallied behind him.

Democrat Judah Nativio ran unopposed for his party's nomination, but the winner of the GOP primary enjoys a big edge in the heavily Republican district.

In other closely watched legislative races:

- House Majority Whip John McComish lost in District 20 in Chandler and Phoenix. One of the two seats was open, spurring aggressive campaigning in a four-way Republican race.

With all 59 precincts reporting, Jeff Dial had 5,269 votes, or 30 percent, Frank Schmuck had 4,824, or 27 percent, McComish had 4,759, or 27 percent, and Andy Swann had 2,846, or 16 percent.

- Moderate Republican Sen. Tom O'Halleran of Sedona lost to conservative challenger Steve Pierce, a Prescott businessman, in the GOP primary in District 1 in Yavapai and Coconino counties. With 101 of 110 precincts reporting, Pierce had 12,280 votes, or 53 percent, while O'Halleran had 10,918 votes, or 47 percent.

O'Halleran had angered business groups by voting against a proposed repeal of a suspended state property tax.

"That decision probably undid him," said Mike Gardner, a former Republican legislator. "Pierce really used that against him."

- Rep. Trish Groe of Lake Havasu City lost in a three-way Republican primary for two seats in District 3 in northwestern Arizona as she tried to put a 2007 misdemeanor DUI conviction behind her. Rep. Nancy McLain won one of the two nominations with 6,826 votes, while Doris Goodale had 6,124 vote and Groe had 5,095.

- Senate Majority Leader Thayer Verschoor defeated term-limited Rep. Eddie Farnsworth in the Republican primary for the Senate seat from District 22 in Gilbert, another Phoenix suburb. With all 70 precincts reporting, Verschoor had 6,100 votes, or 42 percent, Farnsworth had 5,664, or 39 percent and Joe Bedgood had 2,801 votes, or 19 percent.

Verschoor is regarded as a contender for Senate president if Republicans retain control of the chamber.

- Sen. Robert Blendu, R-Litchfield Park, lost in a three-way primary for the two Republican nominations for state House from District 12. The winners were incumbent Rep. Jerry Weiers and newcomer Steve Montenegro.

- Liberal Rep. Pete Hershberger of Tucson faced conservative challenger Al Melvin in the Republican primary race for an open Senate seat now held by a Democrat in District 26 in southern Arizona. With just 10 of 90 precincts reporting, Melvin had 6,019 votes, or 53 percent, and Hershberger had 5,397, or 47 percent.

Pearce was the chief sponsor of Arizona's groundbreaking 2007 law to lift the business licenses of employers that knowingly hire illegal immigrants. Pearce also has championed measures to deny some public services to illegal immigrants and to require crackdowns by state and local law enforcement.

The District 18 Senate race saw several independent groups target Pearce, with some mailings raising questionable charges related to a decades-old allegation of domestic violence and Pearce's past ties - since disavowed - with a white supremacist.

"These are folks who put profit over patriotism," Pearce said of independent expenditure groups that attacked him. "They went after me because I think we ought to obey the law, and it was shameful."

Pearce said he triumphed over "gutter politics" because of voters' familiarity with him and his record of defending taxpayers and family values.

Gibbons said he expected Pearce to do well in a low-turnout primary. He said he counted on support from casual voters who often don't turn out for primaries but who would consider the immigration issue's complexities.

However, "it looks like they did not even show up," he said. "The issue came down to a three-word sound bite from the Pearce side - 'secure the border,' 'enough is enough,' 'cheap labor crowd,' 'profits over patriotism' - that type of thing."

Gardner, the former legislator, said Pearce's critics went too far. "People do have a tolerance level on what's a comparison piece and what's below the belt," he said.

The Senate seat is being vacated because Republican Karen Johnson is retiring.

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