Former Major League Baseball slugger Steve Garvey on Wednesday moved ahead of U.S. Rep. Adam Schiff in California’s U.S. Senate primary – a significant feat despite the November runoff having already been determined.

As of Wednesday morning, Garvey led Schiff by an incredibly slim margin of just 4,801 votes with more than 5 million votes tallied, about 85% of expected returns.

Schiff, one of the leading Democrats in the U.S. House, will face Garvey, a Republican, in November to determine who succeeds the late Sen. Dianne Feinstein. California puts all candidates, regardless of party, on the same primary ballot, and the two who get the most votes advance to the general election.

Whether Garvey retains the lead remains to be seen. However, the former Los Angeles Dodgers and San Diego Padres star attempted to seize the moment.

“As California’s votes are counted, it’s clear that our message of unity, common sense, and compassion resonates across the state,” Garvey said in a statement Wednesday. “I am deeply honored by the trust and support shown in these preliminary results. Our campaign is about bringing together Californians from all walks of life to address our shared challenges.”

The race won’t be finalized until all mail-in ballots are counted, including ballots postmarked last Tuesday.

Garvey’s upstart campaign has surprised many political observers.

Prior to Super Tuesday, all polls showed Schiff with a sizeable lead and Garvey and Democrat Rep. Katie Porter in a tight race for second. As results were released on election night, however, it became immediately clear that Garvey’s support was much stronger than expected.

As of Wednesday morning, Katie Porter (D-Orange County) had roughly 15% of the votes counted.

Republicans account for only about one in four voters in California, so experts say Garvey will need to look to other groups to build a competitive coalition. 

“You can’t run a traditional partisan campaign,” said Ron Nehring, a former state Republican Party chairman. “He cannot take a hyperpartisan or strident ideological approach.”

A Republican hasn’t won a statewide race for any office in California since 2006.

The Associated Press contributed to this report.