Updated 10:07 p.m. CST

According to unofficial results, Dr. Donna Campbell has won the Republican nod for State Senate District 25, ousting long-time incumbent Sen. Jeff Wentworth with 66.18 percent to Wentworth's 33.81 percent with 265 of 286 precincts reporting.

Wentworth said he is disappointed in the results, but he is appreciates his constituents electing him to serve in years past.

"I'm obviously disappointed by the results of today's election, but that sense of disappointment is outweighed by enormous gratitude," he said.

Wentworth said he is proud of the work he has done, having either authored or sponsored 565 bills during his time as a lawmaker. He said he believes the people have "misdirected their fire," and that hurt both him and Texas Lt. Gov. David Dewhurst, who was defeated by Ted Cruz for the Republican nod for one of Texas' U.S. Senate seats.

"The Congress in Washington couldn't even adopt a budget and continued spending money they didn't have by printing it or borrowing it from the Chinese," Wentworth said. "[Voters] should be angry with Washington, not Austin, but they didn't make that distinction."

Updated 8:54 p.m. CST

Dr. Donna Campbell has received the Republican nod for State Senate District 25 based on the unofficial results. The Texas Tribune and Associated Press have both called the race for Campbell over incumbent Sen. Jeff Wentworth, with Campbell bringing in 65.91 percent of the vote with 165 of 286 precincts reporting.

Updated 8:30 p.m. CST

Dr. Donna Campbell has maintained a commanding lead over incumbent Jeff Wentworth in the runoff for the Republican spot for State Senate District 25, taking in 66.35 percent with Wentworth bringing in 33.64 percent of the unofficial results with 101 of 286 precincts reporting.

The Associated Press and the Texas Tribune have both called the race for Campbell.

Updated 8:09 p.m. CST-

According to unofficial results, Dr. Donna Campbell is leading the runoff for the Republican nomination for State Senate District 25 with 66.41 percent to incumbent Jeff Wentworth's 33.58 percent with 43 of 286 precincts reporting.

Wentworth faced off against Campbell and Elizabeth Ames Jones in the May 29 Republican primary.

Wentworth said Campbell's second-place finish was "a surprise to many," on the night of the primary. He and Jones were neck-and-neck for much of the evening before Campbell came from behind to take second place as some of the final precincts' results came in.

Wentworth said he had not been in a runoff since 1992, when he originally won the seat.

Campbell is a physician from New Braunfels who previously ran against eight-term Democratic imcumbent Lloyd Doggett for Texas' 25th Congressional District in 2010, taking 45 percent of the vote.

State Senate District 25 covers all or parts of Kendall, Comal, Guadalupe, Bexar, Travis and Hays counties.

The winner of the runoff will face Democrat John Courage, a San Antonio educator, in the November general election.

Additional reporting by Mitzie Stelte