LOS ANGELES -- Former Major League Baseball MVP Steve Garvey is advancing to a November election to fill the U.S. Senate seat held for three decades by the late Dianne Feinstein, a rare opportunity for the GOP to compete in a marquee statewide race in a Democratic stronghold.

Garvey, a 10-time All-Star who played for the Los Angeles Dodgers and San Diego Padres, will face Democratic Rep. Adam Schiff.

"Let's celebrate," Garvey told his supporters Tuesday night. "Welcome to the California comeback."

"What you all are feeling tonight is what it's like to hit a walkoff home run. Kind of like San Diego in 1984."

Garvey famously hit a walkoff home run off Lee Smith in Game 4 to keep the Padres alive in the 1984 National League Championship Series against the Chicago Cubs. San Diego then won Game 5, and Garvey was named series MVP.

The race is California's first open U.S. Senate contest since 2016. Even before Feinstein announced in early 2023 she would not seek reelection, many of the state's ambitious Democrats were eagerly awaiting their shot at the coveted seat.

Garvey's candidacy, buoyed by name recognition among older voters in particular, threw an unexpected twist into the race. The dynamic between Schiff and U.S. Rep. Katie Porter grew increasingly tense in the campaign's closing weeks as both vied for a general election spot.

The first-time candidate Garvey notched his spot on the fall ballot by positioning himself as an outsider running against entrenched Washington insiders whom he blamed for rising grocery and gas prices, out-of-reach housing costs and an unchecked homeless crisis in cities.

He owes a debt of thanks to Schiff and supportive super political action committees, which ran millions of dollars in advertising spotlighting Garvey's conservative credentials, which indirectly boosted his visibility among Republican and right-leaning voters.

He enters the fall campaign a long shot to fill the seat but touted his prospects at winning come November by using another baseball analogy Tuesday night.

"Keep in mind, this is the first game of a doubleheader, so keep the evening of Nov. 5 open," he told his supporters. "Because we will celebrate again."

The state Republican Party has been in a decades-long tailspin in heavily Democratic California, where a GOP candidate hasn't won a U.S. Senate race since 1988 and registered Democrats outnumber Republican voters by a staggering 2-to-1 margin. Republicans didn't even have a candidate on the general election ballot in the 2016 and 2018 Senate races.

Garvey is hoping to follow a pathway cut by other famous athletes-turned-politicians that includes former California Gov. Arnold Schwarzenegger, a one-time bodybuilder and actor who became the last Republican to hold the state's top job, Utah Rep. Burgess Owens, a former NFL player, and former professional basketball great Bill Bradley, who became a long-serving U.S. senator in New Jersey.

He calls himself a "conservative moderate" and argues he should not be buttonholed into conventional labels, such as former President Donald Trump's Make America Great Again political movement.

Garvey has twice voted for Trump, who lost California in landslides but remains popular among GOP voters, but he has said he hasn't made up his mind about this year's presidential contest. He personally opposes abortion rights but does not support a nationwide abortion ban and will "always uphold the voice of the people," alluding to the state's longstanding tilt in favor of abortion rights.

He also had to overcome the resurfacing of tawdry details about his private life, including having two children with women he wasn't married to, that had undercut the clean-cut public persona he cultivated in his Dodger days.

Information from The Associated Press was used in this report.