Updated at 12:37 p.m.: With all precincts in the district reporting as of 12:37 p.m., Chip Roy is set to face Matt McCall in a runoff election.

Roy finished the night with 19,319 votes, or 27.05 percent of total votes cast. McCall received 12,088 votes, or 16.93 percent of votes in the race.

With 11,088 votes, representing 15.53 percent of voters, William Negley missed the runoff election.

Nine of the 18 candidates in the race received less than 2 percent of votes.

Updated at 10:25 p.m.: With close to 50 percent of precincts reporting across the state, Chip Roy continues to lead the Republican primary for U.S. House District 21.

Roy holds 27.36 percent of the vote as of 10:18 p.m., according to the Texas Office of the Secretary of State website. Matt McCall has surpassed William Negley in a close race for a spot in the runoff election, with 17.23 percent and 16.56 percent respectively.

Update at 9:05 p.m.: Results as of 9:05 p.m., with 53 of 1,031 precincts reporting, show Chip Roy remains in the lead in the U.S. House District 21 Republican primary.

Roy leads with 26.01 percent of votes, followed by William Negley with 17.88 percent and Matt McCall with 17.43 percent of votes.

Following behind the top three are Jason Isaac with 9.19 percent, Jenifer Sarver with 5.72 percent, Robert Stovall with 5.09 percent, Susan Narvaiz with 3.57 percent, Francisco "Quico" Canseco with 3.47 percent and Ryan Krause with 3.02 percent of votes.

Original Post, 8:20 p.m.: In an election that drew 18 candidates, Chip Roy leads the field of Republicans in the U.S. House District 21 primary, according to early voting results released by the Texas Office of the Secretary of State on Tuesday at 8:18 p.m.

Roy leads with 26.57 percent of early votes. William Negley follows in second place with 19.31 percent of early votes.

Matt McCall is the other candidate in the race with over 10 percent of the vote currently, with 14.2 percent.

A total of 31,980 votes have been recorded by the Texas Office of the Secretary of State in the race so far.

U.S. House District 21 Republican primary

Candidates in the race look to replace retiring Rep. Lamar Smith, R-San Antonio, who has served the district since 1987.

U.S. House District 21 covers portions of 10 different Central Texas counties, including Bandera, Bexar, Blanco, Comal, Gillespie, Hays, Kendall, Kerr, Real and Travis.

Republican candidate election results

Chip Roy - 19,319 votes (27.05 percent)
Matt McCall – 12,088 votes (16.93 percent)
William Negley – 11,088 votes (15.53 percent)
Jason Isaac – 7,165 votes (10.03 percent)
Jenifer Sarver – 4,001 votes (5.60 percent)
Robert Stovall – 3,396 votes (4.75 percent)
Susan Narvaiz – 2,710 votes (3.79 percent)
Francisco “Quico” Canseco – 2,484 votes (3.47 percent)
Ryan Krause – 2,289 votes (3.20 percent)
Al M. Poteet – 1,292 votes (1.80 percent)
Peggy Wardlaw – 1,281 votes (1.79 percent)
Samuel Temple – 1,017 votes (1.42 percent)
Anthony J. White – 949 votes (1.32 percent)
Eric Burkhart – 719 votes (1.00 percent)
Mauro Garza – 657 votes (0.92 percent)
Autry J. Pruitt – 454 votes (0.63 percent)
Foster Hagen – 392 votes (0.54 percent)
Ivan A. Andarza – 95 votes (0.13 percent)