SPOKANE, Wash. -- Texas Lutheran Bulldogs captured their first regional championship and will play in the NCAA Division III World Series for the first time in school history after a thrilling 6-5 extra-inning victory Sunday over Willamette (Ore.).

Keaton Boysen's walk-off RBI single in the bottom of the 10th scored Ben Marvin from second base and set off a wild on-field celebration.

The victory secured the sixth-ranked Bulldogs a berth in the NCAA Division III World Series, to be played May 25-30 in Appleton, Wis.

The national championship tournament will be played at Neuroscience Group Field at Fox Cities Stadium.

TLU, making its fifth NCAA post-season appearance, will play in Appleton after coming close to the World Series in 2005 and 2006. The Bulldogs were a win shy of the World Series in those seasons.

Against the Bearcats on Sunday, TLU battled back from a 4-0 deficit. The Bulldogs had only two hits through six innings against Willamette starter Matt Steindorf.

The Bulldogs won for the 10th straight time and improved to 38-9 overall. Willamette's season comes to close at 31-19. Willamette won the Northwest Conference and battled to the championship round as the No. 6 seed.

Marvin (Kingwood/Kingwood) started the winning rally with a walk and advanced to second on a sacrifice bunt from Thomas Varner (Austin/Bowie). After an intentional walk to Tyler Cauley (Baytown/Barbers Hill), Boysen hit the first pitch he saw from the Bearcats relief pitcher Liam Keefe. 

The Bearcats took an early 2-0 lead in the first from two RBI-singles, added runs in the third and sixth innings to give WU a 4-0 heading into the seventh. 

Boysen plated the Bulldogs' first run (unearned) in the seventh. He advanced to third on a Spencer Brandt (Yoakum/Yoakum) single and scored on a Willamette throwing error. 

In the eighth, Varner kicked off scoring with a single to center field. Cauley followed with a two-run homer to left field to tie the game. Matthew Lemon (Caldwell/Caldwell) delivered an RBI double to right center to give TLU a 5-4 lead. 

But the Bearcats were not done. Perry Van Eckhardt led off the top of the ninth with a home run off Dylan Drgac (Caldwell/Caldwell). Van Eckhardt's homer was ruled fair, just inside the right foul pole.

Willamette threatened in the top of the 10th, loading the bases with one out.  Drew Waller (Bellville/Bellville) entered the game and recorded the next two outs. He picked up the win to improve to 5-2.

Boysen finished 2-for-5 with two runs scored and an RBI.  Riley Schaefer (Thorndale/Thorndale) also had two hits for TLU.

Schaefer's first hit came in the sixth inning with a single up the middle. His second hit, a double down the right field line, tied the TLU school record for hits in single-season. Schaefer tied Aaron Merhoff's record of 86 hits, set during the 1999 season.

TLU relievers Cade Killingsworth (Missouri City/North Central Texas), Zach Perry (Round Rock/Round Rock), and Drgac worked a combined 6-1/3 innings and allowed only five hits and two runs.