SACRAMENTO (CBS/AP) – Incumbent Tom Torlakson defeated first-time candidate Marshall Tuck in the hotly contested race for California’s superintendent of public instruction, an election that became an expensive battleground with high stakes for teachers unions and education reformers.

Torlakson is a former high school science teacher and state lawmaker whose re-election the unions had made their top priority in an otherwise ho-hum election for California Democrats.

READ MORE: Downsized But Not Out, Dreamforce Conference Set to Boost Business in San Francisco

“We knew it wouldn’t be easy. They were strong, but we were stronger. They were tough, but we were tougher,” he said, as returns began coming in, after attending an election night party in Sacramento hosted by the California Teachers Association.

California, which educates one-eighth of the nation’s school children, is one of 13 states with an elected K-12 schools chief. It is a largely ministerial office in which the occupant carries out education policies set by the California Legislature and a board appointed by the governor, and in most years the election for it does not make headlines.

The contest between Torlakson, 65, and Tuck, 41, a former charter schools executive, turned into a multimillion-dollar battle due mostly to the challenger’s vocal support for a June court ruling that overturned the state’s generous tenure laws and other job protections for teachers, a position that distinguished him from his opponent. Spending in the race exceeded $22 million, making it the most expensive election for a statewide office apart from the governor’s race.

The election’s outcome was being watched outside California as a referendum on the direction of the state’s underachieving education system and on the powerful role organized labor, especially education unions, has played in the Democratic Party both nationally and in Sacramento.

READ MORE: Emmy Awards: 'The Crown' Dominates with Seven Wins

Torlakson was elected as schools superintendent four years ago after serving 14 years in the state Legislature. In his bid for a second and final term, he had the backing of the unions, the California Democratic Party and the majority of county school superintendents.

Tuck is a former charter schools executive who spent six years leading the Partnership for LA Schools, a nonprofit founded by the former mayor of Los Angeles, Antonio Villaraigosa, that took over 17 urban public schools. He secured endorsements from his former mentor and a handful of other Democratic mayors, as well as all of the state’s major newspapers.

Tuck’s upstart campaign also benefited from at least $10.7 million in independent expenditures by the widow of Apple founder Steve Jobs, former New York Mayor Michael Bloomberg and other business and technology leaders.

Torlakson argued that the state needs steady and experienced leadership as schools rebound from deep budget cuts during the recession and begin to implement curriculum and testing changes associated with new standards.

Tuck, who supports tying students’ standardized test scores to teacher evaluations and merit pay, accused Torlakson of being tied to a failed status quo that prioritized the wishes of the unions over the needs of California’s 6.2 million public school students.

MORE NEWS: Flames Reach Ancient Sequoias; Crews in Pitched Battle to Save Giant Forest Grove

© Copyright 2014 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.