Mark Sanford could get a head start in his primary runoff.

The scandalized former South Carolina governor won Tuesday's 16-way primary for his old House seat, but there's some confusion about whom he'll face in Round 2, a GOP runoff slated for April 2.

With 100 percent of precincts reporting Tuesday night, former Charleston County councilman Curtis Bostic led state Sen. Larry Grooms by 493 votes, which would trigger an automatic recount. With the runoff between the top-two finishers two weeks away, Sanford, 52, could enjoy some lead time in campaigning while his eventual opponent is sorted out.

The South Carolina GOP, meanwhile, has declared that Bostic will advance.

"Mark Sanford and Curtis Bostic both understand that to get our country back on track, we must get our fiscal house in order. South Carolina would be well served by having either man in Congress," state party Chairman Chad Connelly said today in a written statement, congratulating them as the top finishers.

The state party has scheduled a runoff debate for Thursday, March 28.

The South Carolina Election Division lists Sanford and Bostic as the unofficial runoff candidates on its website. But the commission confirmed to ABC News that a recount is scheduled to begin as early as Friday to determine Sanford's runoff opponent. Grooms, a Commission official said, can waive the recount if he notifies the Election Commission in writing.

Grooms, meanwhile, is not conceding, his campaign confirmed to ABC News, despite a Facebook post earlier today in which Grooms had written that his House bid had "ended."

The winner of the April 2 runoff, be it Sanford, Bostic or Grooms, will face Democrat Elizabeth Colbert Busch in the general election May 7.

This post has been updated.