Jacobs, Gardner's chief deputy at the time, had his former boss' support as well as that of the Salt Lake County Republican Party, which picked him over Parkinson in an internal party vote.
An appraisal supervisor in Tooele County, Parkinson contended the operation of the assessor's office is behind the times and that new blood is needed to make it more efficient. Jacobs maintains that his experience and knowledge of the entire system is crucial to ongoing modernization efforts.
Jacobs will face Democrat Tyler Andrus in November.
In the auditor's race, Hatch is attempting to regain the position he lost to Republican Greg Hawkins in 2010. He contends his background in the office will enable him to begin work immediately.
His challenger, Stout, is a businessman whose company advises multinational companies on risk and compliance issues. He previously ran for state treasurer on the Democratic ticket.
Hatch faces Republican Scott Tingley in November.
Outside of Salt Lake County, several other primary races drew light voter interest.
Davis County Republicans lined up solidly behind incumbent Commissioner Bret Millburn, who turned back a challenge from North Salt Lake City Councilman Brian Muir. Millburn received 56 percent of the vote to move on against Steven Andersen, the Democrats' candidate.
In Tooele County, retired Utah State University Extension assistant professor Wade Bitner defeated banker Dean Johnson for the Republican nomination for a county commission seat. He will do battle in November with Democrat Jerry Edwards and independent Jill Thomas.
Tooele will have a new treasurer. Incumbent Jeremy Walker lost to Michael Jensen in the Republican primary. Jensen will advance to face Democrat Rachel Hester.
Meanwhile, GOP voters in Utah County made decisions in four contests.
Bill Lee, a former aide to Sen. Mike Lee, built a fairly comfortable lead early over Lorne Grierson, a business owner, and held it all night.
Two incumbents had little difficulty against their challengers, with county attorney Jeffrey Buhman beating Ben Stanley, while Bryan Thompson won his bid to remain clerk/auditor, brushing aside Jacob Atkins. Kim Jackson also won handily over Cary McConnell in the treasurer's race.
In eastern Utah, Uintah County Commissioner Mike McKee barely survived a primary challenge by Bart Haslam, winning by just nine votes out of more than 4,000 cast. A recount is likely because of the slim margin.